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The  Colorado  Potato  Beetle 


Insects  Injurious 
to  Vegetables 


rlWcHITTENDEN,  SC.  D. 

United  Stales  Department  of  Agrictdture 


ILLUSTRATED 


NEW  YORK 

ORANGE  JUDD  COMPANY 

LONDON 
KEGAN  PAUL,   TRENCH,  TRUBNER  &  CO.,  Limited 

1907 


Copyright  1907 


ORANGE  JUDD  COMPANY 
All  Rights  Reserved 


Entered  at  Stationers'  Hall 
l,ONDON,  England 


PREFACE 

Among  the  hordes  of  insect  foes  with  which  the  American 
farmer  has  to  deal,  those  affecting  vegetable  crops  are  in  many 
respects  most  troublesome.  Vegetable  plants  are  exceptionally 
perishable,  and  the  control  of  their  insect  enemies  entails  a 
very  considerable  expenditure  of  money  and  time.  The  an- 
nual losses  due  to  insect  attack  on  vegetable  crops  is  esti- 
mated at  20  per  cent.,  or  double  that  of  the  average  farm  crop. 
The  injurious  vegetable-feeding  forms  outnumber  in  species  the 
insect  enemies  of  any  other  single  class  of  crops,  excepting 
possibly  deciduous  fruits,  and  this  nearly  endless  variety  of 
pests  necessitates  information  in  regard  to  each.  Many  are 
intermittent  in  attack,  hence  the  grower  should  be  forewarned 
in  order  to  guard  against  injury  or  to  check  it  before  irrep- 
arable damage  has  been  accomplished.  The  progressive  veg- 
etable grower  should  be  as  amply  equipped  with  knowledge 
as  the  fruit  grower,  and  if  he  would  be  entirely  successful  in 
avoiding  losses  from  insect  ravages  he  should  be  provided  with 
a  complete  outfit  for  spraying  operations  and  should  keep  on 
hand  or  know  where  to  obtain  at  short  notice  a  good  supply 
of  necessary  insecticides.  The  more  general  observance  of 
certain  farming  methods  with  a  view  to  the  prevention  of  in- 
sect injury  will  greatly  lessen  the  losses  from  this  source. 
Until  within  recent  years  few  farmers  in  planning  the  manage- 
ment of  the  farm  for  the  season  considered  the  effect  which 
any  given  method  of  tillage  would  have  upon  injurious  insects. 
Too  frequently  they  fail  to  look  far  ahead,  and  as  a  rule  ro- 
tation of  crops  where  practiced  is  more  for  the  sake  of  soil 
improvement  than  for  the  avoidance  of  insect  injury,  and  yet 
crop  rotation  is  the  best  and  sometimes  the  only  remedy  for 


VI  PREFACE 

certain  species  of  insects.  Among  other  general  methods  of 
farming  strict  cleanliness,  including  the  destruction  of  weeds 
and  burning  over  fields  after  harvest,  fall  plowing,  crop  ro- 
tation, the  use  of  fertilizers,  and  the  selection  of  the  proper 
place  and  time  for  planting,  must  be  considered.  A  knowledge 
of  the  classification  of  insects  sufficient  to  enable  the  farmer 
to  distinguish  friends  from  foes  is  valuable,  and  finally  comes 
a  knowledge  of  what  insecticides  and  repellents  to  use  and 
the  best  means  of  preparing  and  applying  them. 

Accounts  of  most  of  our  noxious  species  of  insects  have  been 
published.  These  accounts,  however,  are  distributed  through 
government  and  state  publications,-  reports  of  agricultural  so- 
cieties, magazines,  and  periodical  publications  of«  entomological 
societies,  and  even  the  daily  press.  As  an  example  of  the 
number  of  such  publications  on  American  economic  ento- 
mology, the  Bureau  of  Entomology,  United  States  Department 
of  Agriculture,  has  cited  no  less  than  12,645  titles  that  had 
appeared  to  January  i,  1905,  and  the  number  of  references  to 
noxious  insects  is  about  72,000.  The  average  farmer  has 
neither  time  nor  opportunity  to  consult  a  tithe  of  these  12,- 
000  odd  works,  and  it  is  therefore  the  object  of  the  follow- 
ing pages  to  collate  concise  accounts  of  the  principal  insects 
which  affect  one  class  of  crops — vegetables.  The  order  which 
will  be  followed  is,  as  far  as  practicable,  alphabetical,  begin- 
ning with  the  insect  enemies  of  asparagus,  and  ending  with 
those  which  affect  sweet  potato,  and  finally  miscellaneous  or 
unclassified  crops. 

The  insect  enemies  of  vegetables  have  not  hitherto  been  con- 
sidered as  a  special  topic  in  comprehensive  form.  Separate 
accounts,  however,  on  the  economic  entomology  of  certain 
vegetables  have  been  published,  for  example,  of  beets  and  of 
sweet  potato. 

In  presenting  this  work  to  the  pul)lic  its  author  does  not 
claim  originality  for  its  contents.     It  is,  however,  largely  com- 


piled  from  his  own  writings,  although  it  has  been  found 
necessary  to  draw  also  from  the  works  of  others,  and  is  based 
on  an  experience  of  about  ten  years  with  the  subject  with 
which  it  deals.  The  illustrations  are  in  large  part  the  same,  or 
adaptations  of,  figures  previously  used  in  the  Bureau  of  En- 
tomology, United  States  Department  of  Agriculture,  and  are  so 
credited. 

F.  H.  Chittenden. 
United  States  Department  of  Agriculture, 
September,  iQoy. 


CONTENTS 


PAGE 

Preface v-vii 

Introduction x-xiv 

CHAPTER    I 

Value  of  a  Knowledge  of  Entomology        ....        1-15 
General    considerations — Classification    of   insects — 
Orders  of  insects — Natural  elements  in  the  control 
of  insects. 

CHAPTER    II 

Prevention  by  Farming  Methods 16-25 

Selection  of  place  and  time  for  planting — The  main- 
tenance of  vigorous  growth — Burning  over  fields 
and  waste  lands — Crop  rotation — Diversified  agri- 
culture— Fall  plowing  and  cultivating — Clean  farm- 
ing methods — Farm  inspection — Cooperation  in  the 
control  of  insects. 

CHAPTER    III 

Mechanical  Methods  of  Destroying  Insects  or  Prevent- 
ing Injury 26^29 

CHAPTER    IV 

Insecticides  and  Their  Uses 30-48 

Stomach  poisons,  arsenicals,  etc. — Contact  poisons 
— Insecticides  which  kill  by  sufifocation — Proprie- 
tary insecticides — Insecticide  apparatus — Remarks 
on  applying  insecticides. 

CHAPTER    V 

General  Crop  Pests        .        .        .        .        .        .        .        .      49-91 

Cutworms  and  related  insects — Miscellaneous  cater- 
pillars— Leaf-beetles — Flea-beetles — Blister  beetles — 
Grasshoppers  and  related  insects — White  grubs — 
Wireworms — Aphides,  plant-bugs  and  related  insects 
— The  red  spider. 

CHAPTER    VI 

Insects  Injurious  to  Asparagus         .        „        ,        .        .      93-98 
viii 


CONTENTS  IX 

CHAPTER   VII  PAGE 

Insects  Injurious  to  Beans  and  Peas        .        »        .        .    99-ii9 

CHAPTER   VIII 
Insects  Injurious  to  Beets  and  Spinach  ,        .        .  120-130 

CHAPTER    IX 

Insects    Injurious   to    Cabbage   and   Other   Cruciferous 

Crops I3i-i54 

CHAPTER    X 

Insects    Injurious    to    Cucumber,    Melon    and    Related 

Plants I55-I75 

CHAPTER    XI 

Insects    Injurious    to    Celery,    Parsnips    and    Related 

Plants :  17^188 

CHAPTER    Xll 
Insects  Injurious  to  Sweet  Corn 189-212 

CHAPTER    XIII 
Insects  Injurious  to  Potato  and  Similar  Vegetables        .  213-228 

CHAPTER    XIV 
Insects  Injurious  to  the  Tomato 229-234 

CHAPTER    XV 
Insects  Infesting  the  Sweet   Potato         ....  235-243 

CHAPTER    XVI 

Insects  Injurious  to  Miscellaneous  Vegetable  Crops        .  244-251 
The    onion    and    other   bulb    crops — Rhubarb — Let- 
tuce— Okra   or  gumbo — Salsify — Pepper. 


CHAPTER    XVII 

Bibliography 252-258 

Index 259-262 


INTRODUCTION 


Vegetables  are  subject  to  attack  by  insects  from  the  time 
the  seed  is  planted  until  the  edible  portion  is  ready  for  cooking. 
Insect  injury  manifests  itself  in  different  ways  according  to 
the  plant  attacked,  the  insect  concerned,  the  stage  of  the  insect, 
and  the  age  aiul  condition  of  the  plant. 

Manifestations  of  Insect  Injury. — If  plants  soon  after  the 
seed  has  been  sown  fail  to  appear  in  due  time,  such  failure  is 
apt  to  be  attributed  to  unfavorable  atmospheric 
conditions  or  to  imperfect  seed,  but  examination 
will  frequently  show  that  some  insect  is  at  work. 
Among  insects  destructive  to  planted  seed  are 
wireworms  and  root-maggots,  and  in  some  cases 
insects  that  have  fed  on  the  seed  stock  while  in 
store  are  planted  with  the  seed,  and  this  they 
destroy  by  eating  out  the  germ.  Familiar  ex- 
amples are  the  bean  and  pea  weevils. 

Asparagus    tips    when    ready    for    cutting   are 

ruined  for  market  by  the  asparagus  beetles   (see 

Fig.    1.— Aspara-   ^&-  "^ ) •     ^^  plants  like  tomato  that  are  reset  are 

gus  tip,  showing  cut  ofif  abruptly  near  the  ground,  cutworms  are 

iry^  Asparagus  nearly  always  at  work.     If  the  minute  leaves  of 

beetles.      (Au-  plants    like    cucumber,    soon    after    beginning    to 

thor's     illustra-  ^  ,  •  i  i 

tion.u.s.Dept.  sprout,  are  found  eaten  away,  causmg  the  plants 
Agi")  to   die,   cucumber   beetles   are   present.      Corn    is 

similarly  afifected  by  flea-beetles,  as  are  also  potato  and  other 
vegetables. 

When  stems  or  stalks  of  various  plants  are  found  with  one 
or  more  holes  of  varying  size,  from  that  of  a  straw  to  con- 
siderably larger,  this  is  evidence  of  a  borer  within,  particularly 


INTRODUCTION 


if  excrement  is  exuding.  Common  species  which  do  this  in- 
jury are  the  common  and  corn  stalk-borers  and  the  grass-worm. 
When  plants  like  corn  make  unequal  starts,  a  hill  here  and 
there  showing  greater  thrift  than  elsewhere,  injury  is  apt  to 
be  due  to  root-aphides.  As  a  rule,  these  insects  are  ac- 
companied by  ants,  which  in  most  cases  foster  the  "lice,"  and 
sometimes  feed  on  the  seeds. 

When  the  leaves  of  plants  are  seen  to  be  withering,  and 
aphides  or  other  sucking  insects  cannot  be  de- 
tected above  ground,  search  will  usually  reveal 
the  presence  of  white  grubs,  wireworms  or  other 
insects  working  below  the  surface,  and  the  same 
is  true  of  corn  plants  that  fall  after  windstorms, 
root-worms  also  being  present  at  such  times. 
Another  manifestation  of  the  presence  of  root- 
worms  is  in  the  plants  requiring  too  long  a  time 
for  maturing,  and  producing  sterile  stalks,  and, 
in  the  case  of  corn,  yielding  nubbins  instead  of 

complete  ears. 
When  young 
leaves  are 
found  with 
small  round 
holes  of  about 
the  size  of  a 
pea  or  a  little 
smaller,     leaf- 

beetles  are  usually  present,  while  much  smaller  holes  occurring 
in  great  profusion  over  leaves  usually  betoken  the  presence  of 
flea-beetles.  Extremely  large  and  irregular  holes  in  leaves  of 
older  growth  are  made  by  grasshoppers,  crickets,  and  the  larger 
caterpillars  such  as  "woolly  bears." 

Fruits  such  as  melons  are  attacked  by  the  melon  worm  and 
pickle  worm;  tomato,  beans  and  corn  by  the  bollworm,  tomato 


Fig.  2. 


-Bollworm  entering  bean  pod.    Somewhat  enlarged 
(Author's  illustration,  U.  S.  Dept.  Agr.) 


XU  INTRODUCTION 

fruit  worm  or  ear  worm  (fig.  2),  and  the  edible  roots  of 
such  plants  as  beet  and  carrot,  are  subject  to  injury  by  the 
carrot  beetle,  while  potato  tubers  are  damaged  by  the  potato 
tuber  worm.  Seed  pods  and  similar  coverings  of  seeds  are 
attacked  by  numerous  insects,  such  as  the  corn  ear  worm,  cu- 
cumber beetles,  and  others.  Growing  seeds  are  liable  to  be 
injured  by  some  of  the  last  mentioned  insects  as  well  as  by  some 
others  which  begin  development  when  the  seed  approaches  ma- 
turity. Familiar  forms  are  the  bean  and  pea  weevils,  and  the 
Angoumois  grain  moth. 

Many  other  forms  of  injury  might  be  cited,  but  it  may  suffice 
to  briefly  mention  the  curling  and  dying  down  of  leaves  like 
melon,  due  to  the  presence  of  the  melon  aphis;  the  wilting  and 
dying  of  squash  caused  by  the  severance  of  the  stalks  by  the 
vine  borer  feeding  within;  the  discoloration  of  leaves  such  as 
radish  and  their  subsequent  drying,  owing  to  leaf-miner  attack; 
and  the  destruction  of  whole  plants  of  various  kinds  by  army 
worms  and  migratory  cutworms. 

Every  year  that  passes  brings  with  it  some  new  entomolog- 
ical problem  to  be  solved,  and  this  is  especially  true  of  insect 
injury  to  vegetables.  The  cause  is  usually  a  general  or  local 
outbreak  of  one  or  more  serious  pests,  and  the  species  concerned 
may  be  an  old  and  well-known  injurious  form ;  it  may  be  a  com- 
paratively unknown  species  or  one  that  has  not  hitherto  been 
identified  with  injury  to  useful  plants;  again  the  habits  of  the 
species  may  never  have  been  studied  owing  to  previous  scar- 
city. It  has  perhaps  lived  in  obscurity  since  time  immemorial 
before  any  considerable  outbreak  attracts  attention.  It  may  be 
new  to  our  country  or  even  new  to  science. 

Determination  of  the  Injurious  Insect. — The  first  problem 
that  confronts  the  grower  whose  crops  suffer  from  insect  in- 
jury is  the  identification  of  the  insect.  Most  insects  have 
popular  names,  more  or  less  local,  which  may  be  apt  or  may  be 
rank  misnomers,  conveying  no  definite  meaning. 


INTRODUCTION  XUl 

Thus  if  a  southern  farmer  complain  of  "the  budworm," 
failing  to  state  what  plant  is  being  injured,  it  is  an  impossi- 
bility to  identify  the  insect  concerned.  The  budworm  of  corn 
is  the  twelve-spotted  cucumber  beetle  of  the  northern  states, 
while  the  budworm  of  tobacco  is  the  same  as  the  tomato  fruit 
worm  and  the  corn  ear  worm  or  bollworm  or  a  related  species. 

The  first    pest     is    Diahrotica    12-punctata;    the    second    is 


Fig.  2— Diahrotica  12- 
pundata.  (Riley,  U.  S. 
Dept.  Agr.) 


Fig.  4.— Bollworm  moth  in  natural  position. 
About  twice  natural  size.  (Quaintance, 
U.S.  Dept.  Agr.) 


Hcliothis  obsoleta}  The  parent  of  the  first  is  a  beetle  (fig.  3) 
and  of  the  latter  a  moth  (fig.  4).  It  should  be  added  that  the 
first  named  species  is  also  known  as  drill  worm,  while  the  latter 
is  also  called  the  shatter  worm,  this  last  name  being  shared  also 
by  the  larger  corn  stalk-borer  and  perhaps  by  other  species  hav- 
ing the  same  habits,  such  as  the  fall  army  worm.  The  last  is 
the  grass-worm  of  the  South  and  the   fall  army  worm  of  the 


1  It  is  to  be  regretted  that  the  scientific  names  are  not  more  stable,  but  the 
bollworm  was  generally  recognized  under  the  name  of  Heliothis,  until  it  was 
recently  changed  to  H.   obsoleta. 


XIV  INTRODUCTION 

North.  It  is  the  "alfalfa  worm"  of  Kansas  and  Nebraska  and 
elsewhere  it  is  simply  called  the  army  worm.  Its  technical 
name  is  Laphygma  frugiperda. 

It  will  thus  be  seen  from  the  examples  cited  that  the  popular 
name  of  an  insect  has  frequently  little  bearing  on  its  identity. 
The  scientific  name  must  be  determined. 

A  frequent  source  of  injury  to  plants  is  due  to  contiguous 
growers  who  raise  the  same,  or  similar  crops,  for  different  pur- 
poses, c.  g.,  some  may  raise  cucumbers  for  pickling,  and  in 
the  immediate  vicinity  others  grow  melons  for  fruit,  so  that 
pickle-growers  pick  their  crops  while  quite  young,  and  the 
fruit-growers  when  older.  This  means  that  after  the  pickle- 
grower  has  stopped  pickling,  numerous  vines  remain,  and  the 
insects  scatter  from  them  to  melon  fields. 


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CHAPTER   I 

VALUE  OF  A  KNOWLEDGE  OF  ENTOMOLOGY 

GENERAL   CONSIDERATIONS 

For  an  intelligent  understanding  of  the  subject  of  insect 
control  by  agricultural  practice  one  must  know  not  alone  that 
certain  conditions  produce  an  increase  or  decrease  of  certain 
forms  of  insects,  but  how  this  is  accomplished,  why  the  alter- 
nation of  one  crop  with  another  is  apt  to  result  in  insect 
injury,  and  why  a  system  of  crop  rotation  that  would  be  of 
value  in  the  control  of  one  class  of  insects  might  be  ineffective 
against  another;  how  fall  plowing,  though  destructive  to  one 
species,  would  not  affect  a  different  insect,  and  so  on.  In 
short,  a  knowledge  of  economic  entomology  beyond  the  fact 
that  arsenicals  are  the  proper  remedies  for  mandibulate  or 
chewing  insects,  and  that  kerosene  will  kill  aphides  or  plant- 
lice,  scale  insects,  and  other  soft-bodied  insects,  is  a  prereq- 
uisite to  intelligent  effort  in  the  control  of  noxious  insects. 
Before  we  can  hope  to  avert  losses  we  must  know  what  our 
insect  enemies  are,  what  species  are  destroying  each  crop, 
which  ones  are  responsible  for  primary  injury,  which  are  sec- 
ondary or  merely  auxiliary,  how  injury  is  accomplished,  when 
injury  begins  each  year,  when  it  ends,  as  well  as  other  facts. 

Similarly  desirable  is  it  to  be  able  to  recognize  useful  in- 
sects, such  as  ladybirds,  syrphus  flies,  tachina  and  ichneumon 
flies  and  other  parasites,  that  these  may  not  be  unnecessarily 
destroyed,  but,  if  possible^    encouraged  in  their  useful   work. 


2  INSECTS    INJURIOUS    TU    VEGETABLES 

The  different  stages  of  some  insects  are  so  diverse  that  they 
can  be  identified  only  by  specialists,  and  many  entomologists 
are  unable  to  recognize  them  without  reference  to  technical 
descriptions  and  illustrations.  Some  knowledge  of  the  distri- 
bution and  origin  of  a  species  is  of  value,  as  well  as  some 
acquaintance  with  its  history  and  literature. 

A  knowledge  of  the  life  history  of  an  insect  consists  in 
knowing:  when,  where  and  how  its  eggs  are  deposited;  how  the 
larva  feeds,  and  how  many  stages  there  are  in  this  period;  the 
habits  of  the  larva,  whether  diurnal  or  nocturnal,  whether 
omnivorous  or  a  dainty  feeder ;  how  and  where  it  transforms 
to  pupa;  how  and  where  and  in  what  stage  it  passes  the 
winter;  the  number  of  generations  produced  each  year;  the 
first  appearance  of  the  insect  and  its  disappearance,  and  the 
same  of  each  generation;  its  food  plants,  natural  and  culti- 
vated, and  above  all,  its  favorite  foods,  both  as  larva  and  adult. 
If  to  this  we  add  a  knowledge  of  the  effect  of  farm  practice 
and  of  insecticidal  and  mechanical  methods  on  the  insect  we 
have,  in  a  general  manner,  the  main  facts  desired. 

We  must  determine  in  what  stage  and  at  what  time  the 
insect  is  most  vulnerable,  and  by  practice  and  experiment 
learn  the  best  remedy.  A  knowledge  of  the  appearance  and 
place  of  deposition  of  the  eggs  will,  in  the  case  of  some 
species,  furnish  means  for  their  control,  for  many  insects  can 
be  combatted  successfully  merely  by  destroying  the  eggs. 
Others  may  be  killed  in  their  cocoons. 

The  most  valuable  weapon  that  can  be  used  in  combatting 
an  insect  consists  in  an  intimate  knowledge  of  the  insect  itself 
and  its  life  economy,  its  natural  enemies,  its  susceptibility  to 
natural  influences,  heat  and  cold,  dryness  and  moisture,  and 
their  effect  upon  its  increase  or  decrease  directly,  or  indirectly 
by  destroying  or  favoring  the  growth  of  its  enemies.  A 
knowledge  of  the  weeds  and  wild  plants  that  furnish  food  for 
these  insects,  in  addition  to  cultivated  plants,  and  the  soils  in 


VALUE   OF    A    KNOWLEDGE   OF    ENTOMOLOGY  3 

which  they  attain  their  greatest  development  is  also  desirable. 
To  this  we  must  add  a  knowledge  of  the  etiects  of  different 
farm  practices  upon  the  insects,  as  well  as  of  insecticides. 
There  are  many  insects  with  which  we  cannot  cope  by  the  use 
of  poisonsj  and  it  is  only  by  a  thorough  knowledge  of  their  life 
economy  from  the  time  the  eggs  are  deposited  until  the  perfect 
insect  emerges,  that  we  are  able  to  mitigate  losses  from  their 
ravages.  The  knowledge  of  some  one  or  more  facts  appar- 
ently trivial  in  themselves  may  frequently  enable  us  to  pre- 
vent by  farming  methods  injury  which  we  cannot  cure  by 
means  of  poisons,  mechanical  or  other  direct  methods 

After  seed  has  been  selected  with  reference  to  its  adapta- 
bility to  the  soil  and  climatic  and  other  conditions  one  of  the 
next  problems  that  confront  the  grower  is  how  to  protect  the 
crop  from  noxious  insects  and  diseases.  Fortunately  we  know 
approximately  the  life  history  and  habits  of  a  large  proportion 
of  the  injurious  insect  inhabitants  of  this  country,  with  the 
exception  of  some  few  species  which  have  only  been  recently 
associated  with  injury,  or  which  have  lately  been  introduced 
from  abroad. 

As  a  necessary  preliminary  to  the  discussion  of  the  insect 
enemies  of  the  various  vegetable  crops,  some  idea  of  the  struc- 
ture and  classification  of  insects  must  be  given.  It  is  perti- 
nent to  follow  as  a  matter  of  course  with  general  methods  of 
control,  which  include  (i)  mechanical  methods,  (2)  farm  prac- 
tice as  preventives  and  (3)  the  preparation  and  means  of 
applying  poisons  for  the  destruction  of  insects.  Following 
this  the  different  groups  of  insects  which  affect  various  crops 
and  are  not  attached  to  single  crops  will  be  considered. 

CLASSIFICATION    OF   INSECTS 

If  we  M^ould  have  an  intelligent  understanding  of  the  causes 
that  have  led  to  the  destruction  of  our  crops,  we  must  know 
something  of  the  classification  of  insects  and  their  nearest  rel- 


INSECTS    INJURIOUS   TO   VEGETABLES 


atives  in  order  that  we  may  be  able  to  distinguish  friends 
from  foes  and  true  insects  from  related  forms.  It  is,  of 
course,  not  essential  that  all  of  the  Latin  names  which  insects 
bear  should  be  memorized,  nor  that  anything  approaching  a 
complete  classification  be  studied.  The  object  of  what  is  here 
presented  on  this  topic  is  to  assist  in  the  ready  identification  by 
orders  of  such  creatures  as  may  come  under  observation  as 
enemies  or  suspected  enemies  to  plants  under  cultivation. 

It  is  first  desirable  to  eliminate  animals  which  are  not  true 
insects  but  are  related  to  them.  These  are  all  included  (with 
true  insects)  under  the  branch 
Arthropoda  of  the  Animal  King- 
dom and  are  distinguished  by 
having  their  bodies  composed  of 
rings  or  segments  more  or  less 
similar,  joined  together,  most  of 
them  bearing  jointed  legs,  the  last 
character  separating  them  from 
earthworms,  eel-worms,  or  hair- 
worms, which  have  many  segments 
but  no  legs.  This  branch  is  di- 
vided into  four  classes: 

Crustacea  (Crabs,  lobsters, 
shrimps,  crmvUsh,  and  soz^'-bngs 
\^Oniscid(c'\). — Of  this  class  only  the  sow-bugs  or  pill-bugs  are 
apt  to  be  confused  with  insects,  and  are  of  some  economic 
importance,  though  not  so  injurious  as  many  suppose.  A 
common  injurious  species  is  shown  in  figure  5. 

Arachnida  {Scorpions,  daddy  long-legs,  spiders,  mites,  etc.). — 
The  scorpions  are  well  known  in  the  South  and  need  no  de- 
scription. The  same  is  true  of  the  daddy  long-legs  or  harvest- 
men,  and  spiders  are  everywhere.  Among  the  mites,  however, 
we  have  one  species,  the  so-called  red  spider,  which  is  quite  in- 
jurious at  times  and  which  as  it  is  commonly  supposed  to  be 
an  insect  we  will  treat  in  one  of  the  following  chapters. 


Fig.  5.— Water-cress  sowbug  {Man- 
casellus  brachyuvus).  Enlarged. 
(After  Richardson) 


VALUE   OF    A    KNOWLEDGE   OF    ENTOMOLOGY  5 

Myriopoda  {Thousand-legged  zvonns). — These  creatures  are 
known  to  most  persons,  and  are  divided  into  two  orders:  The 
Centipedes  constitute  a  group  in  which  each  segment  bears 
only  a  single  pair  of  legs,  while  the  body  is  generally  flattened, 
and  the  antennae  are  long  with  many  joints.  They  live  mostly 
by  preying  upon  other  insects.    The  Millipedes  (fig.  6)  have  two 


Fig.  6.— Myriopod.    Enlarged 

pairs  of  legs  to  each  segment  except  the  first  three;  the  body  is 
more  or  less  cylindrical,  and  the  antennae  are  shorter  with  few 
joints.  Most  species  feed  upon  decomposing  vegetable  matter, 
but  some  attack  growing  plants,  more  particularly  those  of 
the  garden  and  greenhouse.  Injury  by  these  creatures,  how- 
ever, is  frequently  exaggerated,  as  in  the  case  of  the  sow- 
bugs,  previously  mentioned. 

Hexapoda  (Insects). — This  brings  us  to  the  true  insects 
which  are  distinguished  from  the  other  three  classes  that  have 
been  mentioned  by  having  the 
body  divided  into  three  distinct 
portions, — head,  thorax  (chest), 
and  abdomen  (belly)  (fig.  7). 
They  have  a  single  pair  of  an- 
tennae or  feelers,  normally  three 
pairs  of  legs,  and  in  the  mature 
stage,  one  or  two  pairs  of  wings 
(save  in  exceptional  cases).  In 
our  present  advanced  state  of 
knowledge   of  the   classification 

of  true  insects  they  have  been  divided  into  no  less  than  nine- 
teen ^  orders,  but   for  present  purposes  what  is  known  as  the 

1  For  a  list  of  these  orders  the  reader  is  referred  to  pp.  77-81  of  Comstock's 
Manual  for  the  Study  of  Insects,   Comstock  Publishing  Co.,   Ithaca,  N.  Y. 


Fig.   7.—Polistes  bellicosus.     Somewhat 
enlarged.    (Marx  del,  U.  S.  Dept.  Agr.) 


6  INSECTS    INJURIOUS   TO   VFX.ETABLKS 

old  Linnsean  classification  will  sufiice.  This  embraces  seven 
orders, — Coleoptera,  Orthoptera,  Lepidoptera,  Hymenoptera, 
Neuroptera,  Diptera,  and  Hemiptcra.  The  first  six  of  these 
orders  are  mandibulate  or  chezving  insects,  at  least  in  the  most 
active  stage  of  the  insect,  while  the  last  are  haustellate  or 
sucking  insects.  This  is  important  to  know  as  on  this  classifica- 
tion depends  the  question  as  to  whether  stomach  poisons,  such 
as  the  arsenicals,  or  contact  poisons,  such  as  kerosene  and  its 
different  preparations,  are  best  suited  for  their  destruction. 

ORDERS  OF  INSECTS 

Coleoptera  or  Beetles. — Beetles  are  distinguished  by  having 
a  pair  of  more  or  less  horny  elytra  or  wing-covers  which  nor- 


Fig.  8.— Convergent  \adyh\rd  (Hippodamia  conuefgens).    a  Adult:  Z?.  pupa, 
c,  larva.    All  much  enlarged.    (Author  s  illustration,  U.  S  Dept   Agr  ) 


mally  meet  in  a  straight  line  down  the  back.  Beneath  them 
are  the  true  membranous  wings,  usually  folded.  The  mouth- 
parts  of  beetles  and  their  larvae  (the  latter  usually  called 
grubs)  are  formed  for  biting.  A  common  beetle,  a  beneficial 
ladybird,  is  shown  in  figure  8,  in  different  stages.  Many  species 
of  beetles  are  injurious  both  in  the  adult  and  larval  stages 
Among  the  best  known  forms  of  this  order  that  injuriously 


VALUE   OF    A    KNOWLEDGE   OF   ENTOMOLOGY  7 

affect  vegetables  are  wirewornis,  white  grubs  and  their  parents 
the  May  and  June  beetles,  leaf-beetles,  flea-beetles,  pea  and 
bean  weevils,  blister  beetles,  bill-bugs  and  other  snout-beetles. 
Lepidoptera  {Butterflies  and  moths). — This  order  consists  of 
insects  having  four  membranous  wings  covered  with  more  or 
less  minute  overlapping  scales.  The  mouth-parts  of  the 
adults   are   formed   for   sucking,   but  the   larvae    (called   cater- 


Fig.  9.— Cabbage  looper  iAutographa  brassicse).  a,  Male  moth:  b,  egg;  c, 
caterpillar;  d,  pupa  in  cocoon,  a,  c,  d,  One-third  larger  than  natural:  b,  more 
enlarged,    (a,  c,  d,  after  Howard;  b,  Chittenden,  U.  S.  Dept.  Agr.) 


pillars,  "worms,"  etc.)  have  well-developed  chewing  mouths. 
The  Lepidoptera  are  of  about  equal  importance  with  the 
Coleoptera  or  beetles   as  pests. 

Examples  of  noxious  forms  that  are  destructive  to  vegetable 
crops  are  found  in  the  cutworms,  army  worms,  webworms, 
cabbage  and  tomato  worms  and  various  caterpillars.  The  cab- 
bage looper  is  shown  in  figure  9  in  its  four  principal  stages. 


8 


INSECTS    INJURIOUS   TO   VEGETABLES 


Hymenoptera  (Sawflies,  ants,  zvasps,  bees,  etc.). — In  this  order 
there  are  two  pairs  of  membranous  wings  with  comparatively 
few  veins,  the  hind-wings  being  the  smaller  pair.  The  mouth- 
parts  of  the  adults  are  formed  for  both  biting  and  sucking, 
and  those  of  the  larvae,  which  are  injurious,  for  biting.  The 
females  are  furnished  with  stings,  piercers  or  saws.  In  this 
order  there  are  comparatively  few  noxious  forms,  and  most 
of  these  are  confined  to  the  sawflies  whose  larvae,  known  as 
slugs  and  false-worms,  consume  vegetation,  doing  injury  similar 


Fig:.  10.— Screw- worm  (Compsomyia  macetlaria).  a.  Maggot;  b,  head  of 
same;  c,  anal  segment  from  rear;  rf,  puparium;  e,  adult  fly;/,  head  from 
side.    All  enlarged. 

to  that  accomplished  by  caterpillars.  Some  species  of  ants 
are  troublesome,  both  directly  and  indirectly,  in  the  latter 
case  by  acting  as  carriers  of  aphides  or  plant-lice,  scales,  and 
some  other  insects.  This  order,  however,  contains  many  bene- 
ficial forms,  such  as  ichneumon  and  chalcis  flies — parasites  of 
noxious  insects,  and  wasps  which  also  destroy  insect  pests. 
One  of  these  is  shown  in  figure  7. 

Diptera,  or  Flies. — Insects  of  this  order  have  a  single  pair 
of  wings  which  are  borne  on  the  mesothorax  or  middle  por- 
tion of  the  thorax.  The  metathorax  or  hind  portion  bears  a 
pair  of  knobbed  thread-like  processes  called  halteres,  poisers, 
or  balancers.  The  mouth-parts  are  formed  for  sucking  in  the 
adult  condition,  but  in  the  larvse   (called  maggots)   the  mouth- 


VALUE   OF   A    KNOWLEDGE   OF    ENTOMOLOGY 


parts  are  for  biting.     To  the  Diptera  belong  such  pernicious 
insects  as  mosquitoes,  house  and  horse  flies,  and  root-maggots. 
For  illustrations  of  the  Diptera,  see  figures  lo  and  20. 
Orthoptera   {Grasshoppers,  crickets,  roaches,  katydids,  etc.). 
— In  this  order  the  insects  have  two  pairs  of  wings, — the  first 
somewhat    horny    and    overlapping    when    at    rest,    the    second 
pair  thin  and  folded  when  at  rest  in  plaits  like  a  fan.     The 
metamorphosis  is  incomplete,  and  all  forms  of  the  insect   (ex- 
cept the  &gg)  are  active,  with  biting  mouth-parts.     The  Rocky 
Mountain  locust  is  an  example  of  this  order   (figs.  11  and  12). 
Hemiptera. — This   order   divides    into    three    suborders, — the 
Heteroptera  or  true  bugs,  the  Homoptera  containing  aphides, 
leafhoppers.  etc.,  and  the  Physopoda  or  thrips.     These  groups 
have    in    common    four    wings, 
the    mouth-parts    in    all    stages 
^^J^^        JfSC —  formed    for    sucking,    with    in- 

complete metamorphoses. 


Fig.  11.  —  Rocky  Mountain  locust 
{Melanoplus  spretus).  a.  a,  Newly- 
hatched  nymph;  b,  full-grown  nymph; 
c,  pupa,  natural  size.  (After  Riley.) 


Fig.  1 2.— Rocky  Mountain  locust  (Melan- 
oplus spretus).  Adult.  Natural  size. 
(After  Riley.) 


Suborder  Heteroptera. — In  the  true  bugs  the  anterior  wings 
are  thickened  at  the  base  and  thinner  at  th^  extremities  and 
overlap  on  the  back,  and  the  beak  arises  from  the  anterior 
portion  of  the  head.  It  includes  various  forms  of  noxious 
insects,  such  as  the  chinch  bug,  numerous  plant-bugs,  (fig.  13), 
squash  bug,  and  certain  beneficial  species,  such  as  soldier-bugs. 

Suborder  Homoptera. — In  this  group  the  wings  are  of  uni- 
form thickness  and  usually  slope  at  the  sides  of  the  body,  the 
beak  arising  from  the  hinder  portion  of  the  lower  side  of  the 
head.  In  this  suborder  most  injurious  pests  are  found  in  the 
aphides  (fig.  14),  leaf-hoppers  and  the  like. 


10 


INSECTS    INJURIOUS   TO   VEGETABLES 


Suborder  Physopoda. — The  thrips  have  two  pairs  of  wings 
of   similar   form — long,   narrow,   membranous,   not    folded,   and 


Fig.   13-— Brown  v>'^Sir\\-h\x^(Euschistus  variolarius).    Adult  at  right;  last 
nymph  stage  at  left.     Enlarged.     (Howard.  U.  S.  Dept.  Agr.) 

with  few  or  no  veins.  These  are  fringed  with  long  hairs  and 
do  not  fold,  but  are  laid  horizontally  along  the  back  when  at 
rest'  (fig.  15)- 

Neuroptera.  —  This  order 
has  been  subdivided  by  re- 
cent writers  into  numerous 
other  orders,  but  as  they  are 
of  comparatively  little  if  any 
economic    importance,    these 


Fig.  14-.— An  aphis.     Much  enlarged 


Fig.  15.— Enthn'ps  Mtici.  a,  Adult  thrips; 
b.  antenna;  c,  leg.  All  highly  magnified. 
(After  Hubbard,  U.  S.  Dept.  Agr.) 


subdivisions  need  not  be  discussed  here.     The   Neuroptera,   in 
fact,  have  served  as  a  "catch-all"  for  the  groups  that  could  not 

1  .\ccording  to  recent  classification  the  Physopoda  constitute  a  distinct  order, 
but  the  Parasitica,  which  includes  the  parasites  of  man  and  other  mammals, 
is  a  suborder  of  equal   rank  with  the  Heteroptera  and   Homoptera. 


VALUE   OF    A    KNOWLEDGE   OF    ENTOMOLOGY 


be  classified  with  other  orders.  Among  neuropteroid  insects  of 
interest  to  the  farmer  are  the  aphis  lions  or  young  of  the  lace- 
winged  flies  (fig.  i6)  which  are  beneficial  by  feeding  on  noxious 
insects  and  the  dragon  flies, 
which  also  do  some  good  in 
destroying  injurious  forms. 

The  Coleoptera,  Lepidop- 
tera,  Hymenoptera,  Neurop- 
tera  and  Diptera  have  what  is  termed  a  complete  metamor- 
phosis, which  means  that  they  undergo  four  totally  different 
stages,  of  Qgg,  larva,  pupa  and  adult  or  imago.     In  the  remaining 


A  lace-wing  with  eggs  at  right 


Fig. 


'■  7.  —Tarnished  plant-bug;  four  stages  of  nymphs.     Enlarged 
(After  Forbes) 


two  orders,  Orthoptera  and  Hemiptera,  the  metamorphosis  is 
incomplete,  which  means  that  in  the  stages  between  the  egg  and 
the  imago  the  insect  undergoes  only  a  gradual  change,  each 
successive  substage  (nymph)  after  the  first  being  very  like  the 
one  that  precedes  or  follows  it  (fig.  17). 


NATURAL  ELEMENTS  IN  THE  CONTROL  OF  INSECTS 

The  benefits  which  the  agriculturist  reaps  from  the  friendly 
assistance  of  various  forms  of  insects  which  prey  upon  nox- 
ious   forms    is    very    considerable.      Every    tiller    of    the    soil 


12  INSECTS   INJURIOUS   TO  VEGETABLES 

should  recognize  their  usefulness,  but  some  are  prone  to  ex- 
pect too  much  from  them  in  the  subjugation  of  farm  pests, 
and  opinions  are  so  diverse  that  the  grower  is  sometimes  in 
doubt  as  to  whether  the  insects  which  are  indicated  as  his 
allies  are  not,  in  reality,  pests.  A  little  study  is  necessary  in 
many  cases  to  discriminate  between  noxious  and  innoxious 
species  and  those  which  are  truly  and  exclusively  beneficial. 

Organisms  beneficial  to  agriculture  may  be  variously  classi- 
fied, but  fall  naturally  into  four  groups.     The  most  important 


Fig.     18-  — Fiery     ground-beetle,    a,   Larva; 


Fig.    19. —A   soldier-bug 
(Milyas  cinctus).    (Riley, 


b,  beetle.    (From  Riley)  U.  S-  Dept.  Agr.) 

forms  are:  (i)  predaceous  insects,  consisting  of  those  which 
feed  externally  upon  their  prey;  (2)  predatory  animals  other 
than  insects,  such  as  birds  and  mammals;  (3)  parasitic  insects 
which  live  in  the  bodies  of  their  hosts;  (4)  fungi  and  diseases 
of  bacterial  origin. 

The  weather  has  quite  as  great  effect  in  the  control  of  in- 
sects as  in  the  yield  of  the  crops  themselves.  Extremes  of  heat 
or  cold,  excess  of  moisture  or  dryness  have  the  same  effect 
on  insect  as  on  plant  life.  The  results  of  severe  rainstorms, 
sudden  cold  snaps  and  prolonged  drought  on  many  insect  pests 
are  well  known. 

Of  predaceous  insects  the  most  useful  are  undoubtedly  the 


VALUE   OF   A    KNOWLEDGE   OF    ENTOMOLOGY  1 3 

ladybirds^  (%•  ^)>  from  their  destruction  of  aphides  alone, 
ahhough  some  forms  also  do  as  good  if  not  even  better  work 
in  limiting  the  numbers  of  scale  insects.  Ladybirds  also  devour 
the  eggs  and  larvae  of  various  other  insects,  and  especially  of 
soft-bodied  forms.  Several  ground-beetles  (fig.  i8)  live  at  the 
expense  of  cutworms  and  other  vegetable-feeding  caterpillars 
and  the  larvae  of  beetles.  Of  this  number  the  great  Lebia^ 
follows  the  Colorado  beetle  wherever  it  goes,  and  appears  to 


Fig.  20.— Syrphus-fly  (Syrphus  ribesii).  a.  Fly;  b,  lateral  view  of  head; 
c.  larva  or  active  immature  form.  All  much  enlarged.  (Author's  illustra- 
tion, U.  S.  Dept.  Agr.) 

have  a  very  considerable  effect  in  limiting  its  overproduction. 
Soldier-bugs"  (fig.  19)  of  several  species  attack  and  kill  soft 
larvae  of  beetles  and  of  moths.  Other  important  predatory 
enemies  of  noxious  insects  are  syrphus  and  robber  flies,  spiders, 
and  daddy  long-legs  or  harvestmen.  The  syrphus  flies*  (fig.  20) 
are  particularly  useful  in  destroying  aphides.  Wasps  of  many 
forms  provision  their  nests  with  the  larvae  of  beetles  and  of 
moths,  and  certain  species  of  mites  help  in  reducing  insects  of 
pestiferous  habits. 


1  Coccinellidae. 


*Lebia  grandis. 


s  Podlsus    spp. 


*  Syrphidae. 


14 


INSECTS    INJURIOUS    TO   VEGETABLES 


Several  kinds  of  birds,  as  also  mammals,  amphibians,  and 
reptiles,  are  well-known  enemies  of  noxious  insects,  and  domes- 
tic fowls  are  of  considerable  value  as  destroyers  of  larvae, 
especially  such  as  are  not  hairy,  like  the  "slugs"  of  asparagus 
and  potato  beetles. 

Among  beneficial  birds,  quail  are  important  enemies  of  such 
pests  as  the  potato  beetle  and  boll  weevil.     Mammals   include 
skunks,   which  kill   great   numbers  of   May  beetles.     Toads  of 
the    amphibians    are    particularly    useful    as    insect    destroyers. 
Chickens,     ducks     and     turkeys 
are  all  used  in  a  practical  way 
by   farmers   for  disposing  of   a 
variety  of  insects.     Turkeys  ap- 
pear to  be  naturally  adapted  as 
substitutes    for    "hand-picking" 
tomato  or  tobacco  worms  and  are 
actually    employed    and    loaned 
for    such    purposes,    and   swine 
are  equally  fitted  for  the  destruc- 
tion of    white  grubs  and  other 
subterranean  pests. 
The    parasitic    enemies    of    noxious    insects    are    legion,    but 
their  activity  as  useful  allies  to  the  farmer  is  to  a  large  extent 
dependent  on  atmospheric  conditions.   As  a  general  rule  also  they 
seldom  appear  in  their  greatest   numbers  until  their   injurious 
hosts  have  done  more  or  less  damage.     Their  principal  useful- 
ness, then,  is  in  so  decimitating  the  numbers  of  noxious  species 
in  one  season  that  few  are  left  to  prey  upon  crops  the  following 
year. 

The  principal  useful  parasites  belong  to  the  family  Hymenop- 
tera,  four-winged  creatures  of  wasp-like  appearance  and  variable 
size.  Of  these  are  the  ichneumon  flies,^  chalcis  flies,^  bra- 
conids,'  the  egg  parasites*  and  some  others. 

1  Ichneumonidse.  •''  Chalcidoidea.  ^  Braconids.  *  Proctotrypidae. 


Fig.  21.  —  Pteromalus  puparum.  Male 
Highly  magnified.  (Author's  illustra- 
tion, U.  S.  Dept.  Agr.) 


VALUE   OF   A    KNOWLEDGE   OF    ENTOMOLOGY 


15 


An  excellent  example  of  the  value  of  parasites  as  insect 
destroyers  is  afforded  by  the  imported  cabbage  worm.  One  of 
its  parasites,  Pteromaliis  puparum  (fig.  21),  destroys  in  some 
seasons  from  80  to  90  per  cent,  of  these  "worms."  Another 
parasite,  Apanteles  glomeratus  was  purposely  introduced  by  the 
United  States  government  about  1883.  During  the  autumn  of 
1904  this  species  held  its  host  under  complete  control  in  the 
District  of  Columbia,  killing  every  "worm"  which  came  under 
the  writer's  observation.     This  species  is  shown  in  figure  2ix. 


Fig.  2 \x.— Apanteles  glomeratus.      a.  Adult  fly;  b,  cocoon;  c,  flies  escaping  from  cocoons 
0,  b,  Highly  magnified,  c,  natural  size.     (Author's  illustration,  U.  S.  Dept.  Agr.) 


CHAPTER    II 

PREVENTION  BY   FARMING  METHODS 

Having  shown  in  a  general  manner  what  is  desirable  for  the 
best  understanding  of  the  subject  under  consideration,  it  is  next 
in  order  to  point  out  how  this  knowledge  may  be  utilized  in  the 
prevention  or  mitigation  of  injury. 

A  knowledge  of  the  origin  and  distribution  of  insects  enables 
us  to  judge  of  the  probable  and  ultimate  spread  of  introductions 
from  abroad  and  from  one  portion  of  our  country  to  another. 
Thus  we  can  predict,  with  a  considerable  degree  of  certainty, 
that  certain  species  will  not  be  injurious  beyond  certain  bound- 
aries, and  that  others  will  widen  their  range  beyond  known 
limits.  Knowing  the  effects  of  atmospheric  conditions,  of  heat 
and  cold,  dryness  and  humidity  upon  insect  reproduction,  we  can 
be  forewarned  of  injury  and  can  plan  accordingly.  Experience 
having  taught  that  the  clearing  of  uncultivated  or  neglected  land 
is  almost  certain  to  be  followed  by  depredations  of  insects  which 
had  inhabited  the  wild  plants  and  weeds,  we  are  enabled  to 
plant  such  crops  as  will  be  least  affected  by  these  insects. 
Knowing  what  insects  are  controlled  by  predaceous,  parasitic  and 
other  enemies,  such  as  beneficial  insects,  contagious  diseases, 
wild  and  domestic  animals,  we  can  in  many  cases,  untilize  these 
natural  agencies  in  our  warfare  against  them. 

Most  of  the  different  farming  methods  which  .vill  be  con- 
sidered are  of  use  in  combatting  insect  enemies  of  cereals ;  in 
short,  without  their  employment  it  is  impossible  to  avoid  losses 
from  these  insects,  as  it  is  seldom  practicable  to  use  insecticides 
on  growing  grain.  The  usefulness  of  many  of  these  methods 
is  due  to  the  slow  spread  of  many  species  except  at  more  or 

i6 


PREVENTION    BY    FARMING    METHODS  I7 

less  regular  periods  of  migration  and  the  strong  tendency  which 
many  have  of  depositing  their  eggs  in  the  same  field  where  they 
have  bred  or  hibernated. 

The  value  of  these  methods  in  the  treatment  of  the  Hessian 
fly  is  summed  up  by  Prof.  F.  M.  Webster  in  the  statement  that 
"four-fifths  of  its  injuries  may  be  prevented  by  a  better  system 
of  agriculture." 

SELECTION    OF   PLACE    AND    TIME    FOR   PLANTING 

With  a  knowledge  of  the  insects  which  attain  their  highest 
development  in  sandy  locatigns,  in  marsh  land  or  in  the  neighbor- 
hood of  woodland,  we  can  prepare  for  attack  from  them  after 
the  ground  has  been  cleared  for  planting.  Much  depends  upon 
a  judicious  selection  of  the  crop  to  replace  weeds  or  to  be  grown 
in  forest  clearings  or  in  land  that  has  long  laid  waste.  Unfortu- 
nately the  crops  frequently  selected  for  planting  in  new  land  are 
the  very  ones  most  subject  to  attack,  and  if  farmers  generally  are 
to  preserve  their  crops  from  insect  injury  they  must  employ  new 
tactics.  Corn  and  other  cereals,  potatoes  and  strawberries  are 
crops  especially  attractive  to  insects  which  have  developed  in 
unused  land.  They  should  therefore  not  be  planted  in  new  land 
until  after  some  less  susceptible  plant  be  used  as  a  first  crop. 
Buckwheat  and  clover  are  less  likely  to  be  injured. 

Corn  should  not  as  a  rule  be  planted  in  marshy  tracts 
or  in  reclaimed  river  beds  owing  to  the  danger  of  injury 
from  bill-bugs,  root-worms,  wireworms  and  the  like.  Nor 
should  corn  follow  wild  grasses,  which  are  liable  to  be  affected 
by  the  same  classes  of  insects  as  well  as  cutworms  and  white 
grubs. 

Next  in  order  is  the  choice  of  the  proper  time  to  plant  to 
avoid  insects  which  are  liable  to  attack  the  crops  which  we  in- 
tend to  grow.  With  early  and  late  planting  must  be  combined 
occasional  planting  between  two  generations  of  an  insect,  and 
the  timely  disposal  of  the  crop,  particularly  if  this  is  damageable. 


l8  INSECTS    INJURIOUS   TO   VEGETABLES 

Late  planting  is  practiced  against  numerous  insects  with  ex- 
cellent success,  the  object  being  to  have  the  crop  appear  after 
the  disappearance  or  dispersion  of  the  insect  whose  ravages  are 
feared.     It  is,  in  fact,  a  standard  remedy  against  some  insects. 

THE  MAINTENANCE  OF  VIGOROUS  GROWTH 

If  plants  be  weakened  through  atmospheric  or  other  cause  or 
through  a  combination  of  unfavorable  conditions  they  are  as  a 
general  rule  more  subject  to  injury  by  insects,  but  there  are 
many  crop  plants,  as  for  example  certain  varieties  of  wheat,  that 
the  ranker  the  growth  the  more  they  are  subject  to  infestation 
by  such  insects  as  the  Hessian  fly. 

Some  have  claimed  that  weak  plants  only  are  subject  to  injury, 
and  that  plants  might  be  grown  by  artificial  methods  for  the 
production  of  such  great  vigor  that  insects  would  not  seriously 
damage  them.  Although  this  might  be  possible  with  a  limited 
number  of  plants,  we  can  not  now  procure  all  of  the  most  favor- 
able conditions.  As  an  instance,  we  have  only  to  cite  the  re- 
ported successful  use  of  kainit  and  nitrate  of  soda  as  a  remedy 
for  wireworms  and  some  other  insects  in  New  Jersey,  and  their 
failure  when  applied  in  other  states.  Possibly  soil  and  atmos- 
pheric conditions  have  in  some  instances  had  some  bearing  upon 
these  failures.    Most  failures,  however,  are  due  to  wrong  methods. 

BURNING  OVER  FIELDS  AND  WASTE  LANDS 
A  farm  practice  in  favor  in  many  regions  against  cereal-feed- 
ing insects  consists  in  burning  over  fields  after  harvest  or  be- 
fore plowing.  It  afifects  particularly  such  insects  as  hibernate 
on  or  just  below  the  ground.  Among  well-known  pests  that 
can  be  reached  by  this  method  are  cutworms,  many  of  which  live 
all  winter  long  above  the  earth's  surface  partially  grown,  also 
webworms,  grasshoppers,  aphides  and  plant-bugs,  and  some 
forms  of  beetles  and  other  insects  which  hibernate  in  the  adult 
stage  at  or  near  the  surface. 


PREVENTION    BY    FARMING    METHODS  IQ 

CROP    ROTATION 

One  of  the  best  of  farming  methods  is  crop  rotation,  as  it 
serves  several  purposes.  If  pursued  on  scientific  principles  it  is 
not  only  a  benefit  to  the  land,  but  is  one  of  the  easiest  means  of 
preventing  attack  from  insects,  fungous  and  other  diseases,  and 
weeds.  In  a  general  way  it  may  be  said  that  crops  of  like  kind, 
that  is.  belonging  to  the  same  botanical  groups,  and  much  sub- 
ject to  insect  attack,  should  not  be  planted  in  successive  years 
in  the  same  fields.  Thus  it  is  inadvisable  to  plant  corn  in  old 
wheat  fields,  and  it  is  equally  unwise  to  grow  small  grains  after 
corn.  Where  insects  occur  like  the  bollworm,  which  attacks 
several  plants,  injuring  tomato  fruit,  corn  ears,  bean  pods,  etc., 
in  similar  manner,  still  greater  care  is  necessary  in  selecting 
the  land  for  planting.  It  follows  that  it  is  bad  practice  to  plant 
corn  after  tomatoes  or  tomatoes  after  corn,  or  to  plant  either 
of  these  crops  in  or  near  cotton  fields. 

Here  is  where  a  knowledge  of  botany  sufficient  to  enable  the 
grower  to  know  the  botanical  families  to  which  his  crops,  as 
well  as  the  weeds,  belong  becomes  of  value;  since  with  the  ex- 
ception of  insects  known  as  general  feeders,  most  species  feed 
by  preference  on  one  or  more  plants  of  the  same  botanical  group. 
Thus  an  insect  destructive  to  cabbage  will  attack  any  cole  crop, 
such  as  turnip  or  radish,  and  weeds  such  as  wild  mustard  and 
pepper-grass ;  hence  care  should  be  used  not  to  plant  cabbage  in 
fields  in  which  the  other  plants  have  grown.  The  same  rule  holds 
with  plants  of  the  cucumber  kind.  Melons  should  not  follow 
squashes,  nor  pumpkins  cucumbers.  Rotation  of  crops  is  prac- 
tically the  only  means  of  dealing  with  some  of  the  most  im- 
portant insects,  among  which  are  the  western  corn  root-worm. 
Where  diversified  farming  is  practiced,  such  leguminous  plants 
as  crimson  clover  and  cowpea  are  most  useful  as  alternates,  be- 
cause valuable  as  soil  restorers,  and  not  as  a  rule  subject  to 
serious  insect  injury. 


20  INSECTS    INJURIOUS   TO   VEGETABLES 

DIVERSIFIED    AGRICULTURE 

Entire  plantings  are  frequently  failures  because  growers  rely 
on  single,  or,  at  best,  two  or  three  crops  for  a  livelihood.  The 
practice  of  growing  large  areas  to  cotton  in'  the  South  is  an  ex- 
ample. Occasionally  this  is  varied  by  corn  or  tobacco,  and  all 
three  crops  are  likely  to  be  injured  by  the  same  insects,  e.  g.,  by 
the  bollworm,  corn-ear  worm  or  tobacco  budworm,  as  this  one 
species  is  variously  termed.  In  Texas  there  was  at  one  time 
the  threatened  danger  of  an  abandonment  of  cotton  culture 
owing  to  the  rapacity  of  the  boll  weevil.  The  large  appropria- 
tions that  have  been  made  available  by  Congress  for  the  con- 
trol of  this  pest  should  result  in  materially  reducing  the  losses 
occasioned  by  it,  which  now  bids  fair  to  seriously  hamper  the 
production  of  this  staple  which  nets  our  country  $500,000,000 
or  more  annually.  The  melon  or  cotton  aphis  has  done  great 
damage  in  Texas  since  the  beginning  of  the  new  century  and 
various  crops  in  the  South  are  threatened  with  new  pests.  It 
is  quite  a  problem,  therefore,  to  decide  what  may  be  grown 
most  advantageously. 

Other  striking  illustrations  of  the  danger  of  cultivating  a 
single  crop  can  be  pointed  out.  In  some  years  in  the  past  it  was 
simply  impossible  for  truckers  in  parts  of  Maryland  and  Virginia 
to  make  a  living  from  cabbage,  or  other  cruciferous  crops  or 
from  melons  and  other  cucurbits,  but  by  growing  several  crops 
of  widely  different  kinds  they  make  a  profit. 

In  the  Northeast  the  farmer  does  not  have  such  problems  with 
which  to  contend  and  yet  raises  many  crops,  keeping  his  hands 
busy  nearly  the  year  round,  and  there  is  no  excuse  for  growers 
in  the  South  and  elsewhere  cultivating  only  a  few  crops  when 
by  diversified  or  general  farming  losses  from  insects,  from  plant 
diseases,  and  from  adverse  climatic  conditions  could  be  avoided. 


PREVENTION    BY    FARMING    METHODS  21 

FALL   PLOWING   AND    CULTIVATING 

One  of  the  best  methods  of  deterring  insects  from  injurious 
attack,  comparable  with  clean  culture,  burning  over,  submersion 
and  the  like,  is  fall  plowing  and  other  ways  of  cultivating.  The 
process  may  be  varied  by  harrowing,  disking,  and  raking,  and 
sometimes  in  cases  of  serious  infestation  a  cross-plowing  is 
advisable.  The  object  of  fall  plowing  is  to  bring  the  insects 
that  are  feared  to  the  surface  where  they  will  be  exposed  to  cold 
and  other  elements  and  to  natural  enemies  such  as  domestic  and 
wild  birds  and  mammals.  This  method  is  particularly  valuable 
to  prevent  the  recurrence  of  severe  attacks  and  is  beneficial  for 
most  forms  of  insects  which  hibernate  under  or  near  the  surface 
of  open  fields,  meadows  and  like  places.  It  is  particularly  indi- 
cated for  many  insects  affecting  cereals,  cucurbits  and  some 
other  vegetables,  and  where  corn  and  other  crops  subject  to 
injury  by  white  grubs,  root- worms  and  wireworms  and  other 
subterranean  insects,  as  well  as  cutworms,  grasshoppers  and 
others,  are  to  be  planted  in  sod  or  weedy  land.  Where  the  forms 
of  insects  mentioned  are  extremely  troublesome,  the  land  should 
be  very  thoroughly  broken,  and  the  insects,  whether  larvae,  pupae, 
or  adults,  should  be  as  much  exposed  as  possible.  This  remedy 
is  very  effective  in  cold  climates  since  the  exposed  insects  are 
unable  to  obtain  secure  shelter  before  severe  frosts. 

Fall  plowing  should  be  practiced  for  most  crops  where  it  does 
not  interfere  with  other  methods  of  cultivation. 

The  numbers  of  the  squash-vine  borer  can  be  greatly  reduced 
by  lightly  harrowing  the  surface  of  infested  fields  after  harvest 
so  as  to  bring  the  cocoons  to  the  surface,  and  then  plowing  in 
the  spring  to  a  uniform  depth  of  six  inches  or  more,  so  that  the 
adults  will  not  be  able  to  issue. 

Disking,  or  cultivation  with  a  disk  harrow,  is  particularly 
recommended  against  the  fall  army  worm,  which  hibernates 
as  pupa  near  the  soil  surface.     A  somewhat  similar  method  of 


22  INSECTS    INJURIOUS    TO    VEGETABLES 

treating  lawns  infested  by  army  worms,  and  root  webworms, 
consists  in  going  over  them  thoroughly  with  a  long-toothed 
steel  rake. 

CLEAN    FARMING    METHODS 

The  most  valuable  of  all  methods  of  controlling  destructive 
insects,  if  we  except  the  employment  of  insecticides,  consists  in 
the  observance  of  clean  cultural  practice,  and  when  with  this 
we  combine  the  judicious  use  of  other  methods,  including  me- 
chanical ones,  only  moderate  use  of  poisons,  employed  at  the 
proper  time,  is  necessary.  It  is  a  more  or  less  complete  safe- 
guard against  the  bulk  of  insects  that  ravage  our  crops. 

Clean  farming  should  always  be  practiced  in  the  growing  of 
crops  that  are  liable  to  severe  insect  injury.  Where  the  char- 
acter of  a  crop  will  permit,  still  more  can  be  accomplished  by 
using  portions  of  the  same  or  a  similar  crop  as  baits.  In  ad- 
dition, it  is  also  desirable  to  employ  as  trap  crops  such  weeds  as 
the  insects  normally  affect  and  which  already  grow  in  the  fields, 
while  in  many  cases  it  has  been  found  of  value  to  plant  weeds 
or  other  crop  plants  to  lure  the  insects  from  the  main  crop. 
Clean  methods  of  management,  though  indicated  as  protective 
against  most  insects,  is  a  practical  necessity  where  there  are 
many  species  that  injure  fall  crops,  such  as  cabbage,  turnip  and 
other  crucifers,  and  for  such  insects  as  pass  the  winter  in  rub- 
bish in  the  fields  that  they  have  ravaged. 

FARM    INSPECTION 

An  old  proverb,  "An  ounce  of  prevention  is  worth  a  pound  of 
cure,"  is  as  applicable  to  man  in  relation  to  insects  which  injure 
his  crops  as  to  other  matters  which  affect  his  well-being.  Eter- 
nal vigilance  is  also  the  price  of  a  good  crop.  The  fact  that 
the  greatest  injury  due  to  such  insects  as  army  worms,  cut- 
worms, blister  beetles  and  the  like  is  accomplished  before  their 
presence  is  known,  indicates  the  value  of  prompt  action  in  the 
treatment  of  the  crops  affected.     Too  frequently  attack  is  un- 


PREVENTION    BY    FARMING    METHODS  23 

noticed  until  damage  is  beyond  repair,  and  this  might  be  averted 
if  the  grower  would  only  employ  some  simple  farm  practice  like 
fall  plowing. 

Promptness  cannot  be  too  strongly  urged,  for  the  application 
of  remedies  if  too  long  deferred  may  be  useless.  As  soon  as  a 
crop  is  planted  it  should  be  inspected  every  few  days  for  signs 
of  injury.  If  plants  growing  under  the  same  conditions  make 
unequal  growth,  over  a  considerable  area,  the  backward  plants 
should  be  examined  for  evidence  of  insect  work.  Insect  injury 
is  manifested  in  different  ways,  as  has  already  been  described 
in  the  Introductory  Chapter  (page  x). 

After  crops  have  made  some  growth,  a  weekly  inspection  will 
in  ordinary  cases  suffice  until  the  danger  point  has  passed;  and 
as  attack  usually  begins  on  the  borders  of  a  field,  by  walking 
around  it  most  forms  of  insect  injury  may  be  detected.  Pre- 
ventive work,  such  as  clean  culture,  rotation  and  fall  plowing, 
should  be  instituted  as  a  part  of  the  routine  of  farming;  and  if 
systematically  pursued  losses  through  insect  ravages  will  be 
reduced  to  a  minimum;  while  prompt  action  at  the  very  outset 
of  attack,  in  the  application  of  insecticides  or  mechanical 
methods  will,  in  exceptional  cases,  save  the  crop. 

COOPERATION    IN   THE    CONTROL    OF   INSECTS 

The  grower  who  institutes  practical  methods  for  the  control 
of  insects  which  menace  his  crops  has  a  distinct  advantage  over 
one  who  does  not.  The  enterprising  farmer  is  enabled  to  ob- 
tain a  good  yield  while  the  careless  grower  stands  a  chance  of 
a  money  loss  on  his  crop.  It  has  long  been  recognized  that 
insects  of  many  forms  are  a  direct  benefit  to  the  progressive 
man,  who  farms  on  scientific  principles,  enabling  him  to  pre- 
serve his  crops  while  the  damage  that  may  be  done  to  his  more 
careless  neighbors  enhances  the  market  value  of  what  the 
scientific  farmer  raises.  This  is  a  decidedly  narrow-minded  and 
selfish  way  of  looking  at  the  subject. 


24  INSECTS    INJURIOUS   TO   VEGETABLES 

Large  corporations  like  seedsmen,  canners,  and  picklers,  plant 
very  extensive  areas  and  employ  others  in  growing  the  same 
crops.  Such  firms  provide  seed  and  machinery,  and  keep  posted 
on  what  will  benefit  not  only  their  own  interests,  but  those  who 
labor  for  them.  This  applies  to  the  means  of  controlling  in- 
sects, including  the  purchase  of  insecticides  and  spraying  ap- 
paratus, and  by  purchasing  at  wholesale  they  greatly  reduce  the 
cost  for  themselves  and  their  co-laborers.  The  scope  of  this 
wOrk  might  be  extended  (and  perhaps  is  in  use  in  some  measure) 
to  those  who  grow  on  a  smaller  scale,  the  farmers  of  a  given 
locality  having  a  community  of  interests  pooling  their  interests 
for  the  purpose.  Growers  having  small  areas  are  often  so 
little  troubled  with  insects  that  it  does  not  pay  to  buy  expensive 
outfits;  and  insecticides  cost  at  retail  frequently  two  or  three 
times  as  much  as  when  purchased  in  quantity.  For  example, 
bisulphid  of  carbon,  a  standard  remedy  for  the  melon  aphis, 
bean  and  pea  weevils  and  root-maggots,  costs  only  lo  cents  a 
pound  in  fifty-pound  lots,  and  from  20  to  30  cents  when  bought 
in  smaller  quantity.  This  difference  could  be  saved  by  the  co- 
operation of  several  neighbors,  and  it  could  be  extended  to  the 
purchase  of  expensive  spraying  outfits. 

Co-operation  is  of  especial  value  in  the  control  of  insects  such 
as  the  squash  bug,  cucumber  beetle,  harlequin  cabbage  bug,  and 
cabbage  looper,  that  cannot  be  held  in  subjection  by  ordinary 
poisons.  If  growers  who  suffer  most  could  induce  neighboring 
farmers  to  employ  clean  farming  methods  and  crop  rotation,  the 
ravages  of  these  pests  would  be  greatly  reduced.  The  harlequin 
cabbage  bug  is  quite  resistant  to  poisons,  and  since  about  the 
year  1900  it  has  been  so  nearly  exterminated  in  its  northern 
range,  that  if  farmers  would  work  together  when  it  again  makes 
its  appearance  northward  and  use  trap  crops  over  large  areas, 
for  example  over  townships,  the  insect  might  be  prevented 
for  several  more  years  from  regaining  its  lost  foothold.  This, 
with  clean  methods  of  cultivation,  would  leave  little  else  neces- 


?BTv  tmxARY 


PREVENTION    BY    FARMING    METHODS  2$ 

sary  to  keep  the  insect  down,  unless  by  carelessness  it  were 
permitted  to  return  unmolested  to  its  old  haunts.  Immeasurable 
benefits  would  undoubtedly  accrue  by  the  subordination  of  self- 
interest  for  the  common  weal.  Indeed  this  subordination  is  only 
apparent  and  it  has  been  pointed  out  that  one  of  the  best,  as  it 
is  the  noblest,  methods  of  self-help  consists  in  helping  our 
fellow  men. 


Fig.  2I3'.— A  simple  coal-tar  pan  to  be  drawn  by  hand      1  After  Riley) 


CHAPTER    III 

MECHANICAL  METHODS  OF  DESTROYING 
INSECTS  OR  PREVENTING  INJURY 

Many  valuable  mechanical  methods  of  controlling  insects  are 
employed,  such  as  hand-picking,  "bugging"  or  beating,  collecting 
in  nets  or  in  hopper-dozers,  ditching,  disking,  driving  and  others. 

Hand-picking  is  useful  for  large  conspicuous  inactive  insects, 
such  as  the  squash  bug,  potato  beetle,  cutworms  and  similar 
caterpillars.  It  is  one  of  the  simplest  measures  that  can  be  em- 
ployed, and  is  valuable  where  other  means  cannot  be  used  and 
where  labor  is  cheap. 

Bugging. — This  term  is  often  used  for  jarring  and  beating  in- 
sects from  low  plants  into  pans  containing  water  and  a  thin 
scum  of  kerosene.  The  water  prevents  the  insect  from  es- 
caping, and  the  floating  kerosene  kills  every  insect  which  comes 
in  contact  with  it. 

Collecting  in  nets. — Hand  nets  of  muslin  or  cheese-cloth  such 
as  school  children  employ  for  the  capture  of  butterflies,  are  use- 
ful against  some  insects  which  affect  truck  crops.  Among  such 
are  the  tarnished  plant-bug,  which  affects  about  equally  vege- 
tables and  small  fruits.  By  sweeping  over  the  plants  to  be 
protected  and  the  weeds  and  grasses  of  the  vicinity,  thousands 
can  be  captured  in  a  short  time,  and  they  can  then  be  killed  by 
throwing  them  into  a  fire  or  into  hot  water. 

Collecting  in  hojyper-dozer.'i. — Many  forms  of  these  death-deal- 
ing devices  are  in  use  for  grasshoppers  (see  figs.  2iy  and  2iz) 
and  for  leaf-hoppers,  which  will  be  described  in  the  discussion 
of  those  insects. 
26 


MECHANICAL    METHODS    OF    DESTROYING    INSECTS  27 

Brushing  methods.— Difiereni  methods  of  brushing  more  or 
less  skiggish  insects  from  their  cultivated  food  plants  have  been 
in  vogue  for  many  years.  Potato  beetles  and  their  larvae  may 
be  brushed  from  potato  plants  by  means  of  a  short-handled 
broom,  a  second  person  to  follow  dragging  by  horse  power  a 
bundle  of  brush  or  a  harrow  to  crush  the  insects  and  bury  them. 
This   process   is   simplified   in   the   treatment   of   the   asparagus 


Fig.  21^.— A  canvas  hopper-dozer  to  be  drawn  by  horse,     (After  Riley) 

beetles.  It  consists  in  beating  or  brushing  the  insects  from  the 
plants  with  a  stick  so  that  they  will  drop  to  the  bare  ground 
on  a  hot  dry  day.  The  larvae  are  delicate  creatures,  crawl  very 
slowly,  and  few  are  able  to  regain  the  shelter  of  the  plants  and 
die  from  exposure  to  the  heated  earth.  A  somewhat  more  com- 
plicated system  came  into  rather  extensive  use  in  1900  against 
the  pea  aphis.  It  is  known  as  the  brush  and  cultivator  method, 
and  at  the  time  of  writing  is  the  best  remedy  that  has  been  de- 
vised for  this  pernicious  species.  It  will  be  described  in  dis- 
cussing pea  aphis  remedies. 

Cloth  covering. — To  prevent  injury  from  some  forms  of  in- 
sects to  young  plants  before  they  are  fairly  above  ground  early 
in  the  season  cloth  coverings  are  used.    A  cheap  frame  may  be 


28  INSECTS    INJURIOUS   TO   VEGETABLES 

made  by  cutting  a  barrel  hoop  in  two  so  as  to  form  two  semi- 
circles, which  are  then  placed  at  right  angles  to  each  other,  and 
the  lower  ends  inserted  into  the  ground  with  the  curve  upper- 
most. This  is  then  covered  with  gauze  or  similar  material,  held 
in  place  with  earth  packed  about  the  edges,  to  prevent  the 
beetles  working  under  it.  It  is  necessary  to  keep  the  plants 
covered  only  while  they  are  young,  and  the  same  covering  may 
be  used  year  after  year.  Such  covers  are  much  used  against 
the  striped  cucumber  beetle,  and  radishes  have  been  successfully 
protected  from  root-maggots. 

Trapping. — Several  methods  of  trapping  insects  are  practiced 
with  success.  Trapping  under  boards,  shingles,  chips,  etc.,  is 
useful  for  squash-bugs  and  cutworms  and  if  employed  properly 
will  serve  as  a  means  of  destroying  many  pests.  In  the  case 
of  cutworms  poisoned  baits  are  placed  under  such  traps. 

Pruning  and  the  destruction  of  affected  parts,  practiced  with 
benefit  against  many  tree-borers,  are  useful  methods  for  killing 
some  vegetable  feeders,  e.  g.,  aphides  or  "lice"  when  congre- 
gated on  seedstalks  of  crucifers,  etc. 

Miscellaneous  mechanical  remedies. — Such  remedies  as  ditch- 
ing, disking  and  driving  are  applicable  to  only  a  few  forms  of 
insects  and  will  be  mentioned  in  the  body  of  the  present  work  as 
remedies  for  those  insects  where  described.  Ditching  is  prac- 
ticed against  the  army  worm,  as  is  also  disking,  and  such  insects 
as  blister  beetles  and  cucumber  beetles  may  be  driven  by  various 
means  from  cultivated  fields. 

Repellents. — Various  substances  have  been  advised  in  the  past 
and  are  claimed  by  "knowing  ones"  to  be  valuable  as  preventives 
of  insect  attack,  but  comparatively  few  deterrents  will  stand  a 
thorough  test  The  best  for  use  on  vegetable  crops  will  pres- 
ently receive  mention  because  of  their  value  as  insecticides  or 
fungicides.  These  are:  Tobacco;  carbolic  acid,  used  in  emul- 
sified form ;  Bordeaux  mixture ;  kerosene  emulsion ;  sulphur, 
when  freshly  applied;  and  fish-oil  soaps.    Certain  substances  like 


MECHANICAL    METHODS   OF   DESTROYING   INSECTS  29 

ashes  and  road  dust,  finely  pulverized  and  sifted  on  young  leaves 
serve  to  drive  insects  to  other  clean  leaves  which  should  be 
poisoned.  Substances  which  are  of  little  or  no  practical  use  as 
repellents,  for  vegetable  insects  at  least,  are  legion.  Among 
those  for  use  as  topdressings,  or  about  the  soil  of  the  plants, 
which  do  not  commend  themselves  or  which  produce  indifferent 
results  are :  Bone  dust,  soot,  coal  dust,  liver  oi  sulphur,  lye,  ben- 
zine, naphtha,  naphthaline,  alum  water,  salt,  saltpetre,  etc. 

Bordeaux  mixture  is  one  of  the  most  valuable  insect  deter- 
rents and  is  particularly  useful  for  flea-beetles,  leaf-beetles  and 
other  foliage-feeders.  Its  value  as  a  fungicide  is  too  well  known 
for  further  comment.     The  formula  follows: 

Into  a  50-gallon  barrel  pour  30  gallons  of  water,  and  sus- 
pend in  it  6  pounds  of  bluestone  in  coarse  sacking.  Slake  4 
pounds  of  fresh  lime  in  another  vessel,  adding  water  slowly 
to  obtain  a  creamy  liquid,  free  from  grit.  When  the  bluestone 
is  dissolved  add  the  lime  milk  slowly  with  water  enough  to 
fill  the  barrel,  stirring  constantly. 

With  insufficient  lime  the  mixture  sometimes  injures  the 
foliage,  and  it  should  be  tested  with  a  solution  obtained  by  dis- 
solving an  ounce  of  yellow  prussiate  of  potash  (potassium  fer- 
rocyanide)  in  one-half  pint  of  water.  If  there  be  insufficient 
lime  in  the  Bordeaux  mixture  the  addition  of  a  drop  or  two 
of  this  solution  will  cause  a  brownish-red  color,  and  more  lime 
should  be  added  until  no  change  takes  place  when  the  solution 
is  dropped  in.  Use  the  Bordeaux  mixture  promptly,  as  it  de- 
teriorates on  standing. 

Stock  solutions  of  both  the  bluestone  and  lime  may  be  kept 
for  any  length  of  time.  Make  the  stock  bluestone  by  dissolving 
in  water  at  the  rate  of  2  pounds  to  the  gallon.  The  stock  lime 
is  slaked  and  kept  as  a  thick  paste.  Cover  both  mixtures,  to 
prevent  evaporation  and  keep  the  lime  moist.  For  the  50-gallon 
formula  add  3  gallons  of  the  bluestone  solution  to  50  gallons 
of  water,  and  introduce  the  stock  lime  slowly  until  there  is  no 
reaction  with  the  testing  solution. — Galloway. 


CHAPTER    IV 


INSECTICIDES  AND  THEIR  USES 

The  most  approved  means  of  controlling  insects  consists  in 
the  use  of  poisonous  mixtures  administered  in  the  form  of  a 
spray,  wash,  or  dry  powder  in  conjunction  with  such  methods  of 
farming,  as  fall  plowing  and  rotation  of  crops,  which  tend  to 
decrease  the  chances  of  injury  from  insect  attack. 

Insecticides,  or  the  substances  used  for  the  destruction  of  in- 
sects, may  be  classified  as  internal  or  stomach  poisons,  and  ex- 
ternal or  contact  poisons.  The  former  kill  by  being  eaten  with 
the  insects'  food,  the  latter  by  direct  contact  causing  corrosion 
of  the  bodies  of  the  insects,  or  the  closing  of  their  breathing 
pores. 

STOMACH   POISONS,  ARSENICALS,   ETC. 

Paris  green. — Of  the  various  internal  poisons  in  use  against 
insects  none  are  so  valuable  or  so  much  used  as  Paris  green,* 
the  standard  remedy  against  biting  or  chewing  species,  which 
include  the  bulk  of  injurious  forms,  such  as  cutworms  and  other 
caterpillars,  beetles,  grubs,  slugs,  etc.  Paris  green  is  applied  in 
two  ways, — dry  and  as  a  spray,  the  latter  being  the  method 
most  extensively  used,  as  it  is  cheaper  and  more  effective, 
answering  all  the  purposes  to  which  dry  powders  are  put.  A 
spray  is  prepared  by  combining  one  pound  each  of  the  poison 
and  fresh  slaked  or  quick  lime  with  from  75  to  150  gallons 
of  water.     A  slight  excess  of  lime  is  advisable.     A  somewhat 

1  Paris  green  is  now  chemically  known  as  copper  accto-arsenite ;  in  other 
words,  it  is  a  chemical  compound  of  oxid  of  copper,  acetic  acid  and  arsenious 
acid,  and  when  properly  combined  the  proportions  of  the  different  chemicals 
are  as  follows:  copper  oxid,  31.29  per  cent.;  acetic  acid,  10.06  per  cent.; 
arsenious  acid,  58.65  per  cent. 

30 


INSECTICIDES   AND   THEIR   USES  3I 

Stronger  mixture  can  be  used  on  resistant  plants  like  potato,  and 
a  weaker  solution  (i  to  200)  must  be  made  for  young  and 
delicate  foliage. 

For  the  proper  preparation  and  application  of  this  and  other 
sprays  a  sprayer  or  spray  pump  is  necessary.  The  Paris  green 
should  first  be  mixed  with  a  small  quantity  of  water  into  a  thin 
paste  before  the  bulk  of  the  water  is  added,  and  should  then  be 
thoroughly  mixed  by  churning  in  the  force-pump.  As  the  mix- 
ture is  only  a  mechanical  one  the  Paris  green  tends  to  sink  to 
the  bottom,  and  to  avoid  this  it  must  be  constantly  stirred  while 
being  applied,  otherwise  the  mixture  near  the  bottom  of  the 
tank  or  reservoir  will  become  so  strong  as  to  scorch  the  foliage. 
Care  should  be  exercised  in  the  purchase  of  a  spray  pump  that 
it  be  equipped  with  a  proper  agitator. 

When  applied  dry,  it  is  generally  mixed  with  from  10  to  20 
parts  of  flour,  plaster,  "or  lime.  This  remedy  affords  best  results 
early  in  the  season  on  young  plants.  It  should  be  dusted  on 
preferably  when  the  dew  is  on,  or  after  a  shower,  and  by  means 
of  powder  guns  or  bellows,  or  the  so-called  "dust-spray"  ma- 
chines, so  as  to  cover  the  plants  and  leave  as  little  surface  as 
possible   for   food  for  the  first-appearing  insects. 

It  is  often  advisable  to  use  P)ordeaux  mixture  in  combination 
with  an  arsenical,  especially  if  a  disease  is  present.  This  is 
a  valuable  insect  repellent  as  well  as  a  standard  fungicide,  and 
it  operates  also  against  different  forms  of  blight  and  other 
diseases  which  may  threaten  the  crop.  It  is  used  as  a  diluent 
instead  of  water  and  in  the  same  proportions,  and  prevents 
scorching.     Its  preparation  is  discussed  on  page  28. 

Paris  green  is  more  usually  recommended  for  general  pur- 
poses because  it  is  known  to  most  farmers,  can  be  obtained  in 
drug  stores  anywhere,  and  because  of  its  supposed  cheapness. 
Its  use,  however,  is  being  superseded  in  some  degree  by  arsenate 
of  lead  and  other  arsenicals. 

Paris  green  is  very   frequently  adulterated  by  unscrupulous 


32  INSECTS    INJURIOUS   TO   VEGETABLES 

dealers,  e.  g.,  with  white  arsenic,  which  makes  the  liquid  mixture 
(containing  an  excess  of  free  arsenic)  still  more  scorching  m 
its  effects  on  vegetation.  The  New  York  (Geneva)  Experiment 
Station  has  ascertained  that  this  insecticide  possesses  about  one- 
third  the  fungicide  value  of   Bordeaux  mixture. 

Arsenate  of  lead,  lead  arsenate  or  "disparene"  has  the  ad- 
vantage of  being  less  harmful  to  growing  plants  and  adheres 
better  to  the  leaves  than  other  arsenicals.  It  is  less  apt  to  burn 
delicate  foliage,  hence  does  not  require  the  same  care  in  its 
application  as  is  necessary  for  Paris  green,  and  can,  moreover, 
be  obtained  ready  made  on  the  market.  Numerous  brands  are 
for  sale,  and  care  should  be  exercised  to  obtain  a  good  quality 
as  some  alleged  arsenate  of  lead  preparations  contain  free 
arsenic.  The  commercial  preparations  are  mostly  like  paste  or 
putty  and  must  be  worked  in  a  little  water  in  a  bucket  before 
being  added  to  the  spray  tank. 

It  is  prepared  by  combining  acetate  of  lead  (6  or  7  parts) 
with  arsenate  of  soda  (3  parts).  In  spraying  it  can  be  employed 
at  any  strength  from  3  to  as  high  as  12  pounds  to  100  gallons 
of  water  without  injury  to  most  vegetable  crops.  Its  cost  at 
present  writing  is  12  to  i^  cents  a  pound  when  purchased  in 
bulk.  Quite  a  number  of  other  arsenicals  have  been  more  or 
less  used  as  insecticides  and  some  of  these  are  of  considerable 
value  while  others  have  no  especial  advantages  over  Paris  green 
or  arsenate  of  lead,  or  are  decidedly  inferior. 

London  purple  was  formerly  used  in  spraying.  As  sold  in 
the  market  its  composition  is  unstable  owing  to  its  being  apt 
to  be  adulterated,  and  it  is  very  caustic,  hence  liable  to  scorch 
tender  foliage.  For  these  reasons  it  is  rapidly  going  out  of 
use.  As  a  spray  it  is  applied  in  the  same  proportions  as  Paris 
green,  as  is  also  arsenite  of  copper. 

Arsenite  of  copper  (Scheele's  green  or  "green  arsenoid")  is 
of  -similar  composition  to  Paris  green,  and  is  even  superior 
owing  to  its  more  rapid  effects  and  less  liability  to  produce 
scorching.     It  is,  however,  not  as  yet  so  readily  obtainable. 


INSECTICIDES   AND   THEIR   USES  33 

White  arsenic  (pure  arsenious  acid)  is  the  active  principle 
of  all  the  arsenicals.  It  is  particularly  dangerous  when  used 
alone  in  solution,  but  as  it  is  the  cheapest  of  the  arsenicals  it  is 
employed  in  the  preparation  of  poisoned  baits  for  cutworms  and 
grasshoppers.     Combined  with  lime  it  forms  arsenitc  of  lime. 

Arsenite  of  lime  has  been  highly  recommended  by  those  who 
have  tried  it.     It  is  prepared  by  such  methods  as  follow : 

The  Kedzie  formula :  Boil  2  pounds  of  white  arsenic  and  8 
pounds  of  sal-soda  15  minutes  in  2  gallons  of  water.  Put  into 
a  jug,  label  "poison"  and  lock  it  up.  When  ready  to  spray, 
slake  2  pounds  lime  and  stir  into  it  40  gallons  water,  adding 
a  pint  to  a  quart  of  the  mixture  from  the  jug. 

Formula  No.  2 :  Boil  together  i  pound  white  arsenic,  2  pounds 
lump  or  stone  lime  and  3  gallons  water.  Dilute  with  about 
200  gallons  of  water  before  spraying. 

Still  other  arsenicals  possess  insecticidal  properties.  Of  these 
"pink  arsenoid"  has  given  good  results  experimentally.  "White 
arsenoid"  has  been  practically  withdrawn  from  the  market. 
"Paragrene"  is  reported  as  having  equal  insecticide  value  with 
Paris  green,  is  about  as  likely  to  burn  foliage,  but  remains 
longer  in  suspension.^ 

The  arsenicals  are  also  useful  in  the  preparation  of  poisoned 
baits,  which  will  be  discussed  in  the  consideration  of  cutworms 
and  locusts  or  grasshoppers. 

Harnilessness  of  arsenicals  when  properly  applied. — Chemical 
analysis  has  shown  that  cabbage  which  has  been  dusted  or 
sprayed  with  an  arsenical  in  the  way  prescribed,  and  then 
prepared  for  cooking  in  the  usual  manner  a  week  later  has  not 
even  a  trace  of  arsenic  remaining.  The  use  of  arsenicals  against 
cabbage  worms  is  almost  universal,  although  growers  are  some- 
times loath  to  acknowledge  the  fact  for  fear  of  the  loss  of 
customers  who  are  not  fully  acquainted  with  the  harmlessness 

More    detailed    directions    for    the    preparation    of    the    arsenicals    here    dis- 
cussed are  given  in   Farmers'   Bulletin   127,   U.   S.   Department  of  Agriculture. 


34  INSECTS    INJURIOUS    TO   VEGETABLES 

of  this  remedy.  There  are  no  authentic  recorded  instances 
known  to  the  writer  of  poisoning  from  the  consumption  of 
cabbage  or  other  vegetables  treated  with  an  arsenical.  Ac- 
cording to  Gillette,  28  cabbages  dusted  in  the  ordinary  way 
would  have  to  be  eaten  by  a  human  being  at  one  meal  in  order 
to  produce  poisonous  effects !  It  is  preferable,  however,  in 
order  to  avoid  all  danger,  to  use  other  insecticides  in  the  case 
of  vegetables  soon  to  be  eaten. 

Caution. — It  is  advisable  in  using  all  arsenicals  to  see  that 
they  are  correctly  labeled  and  kept  under  lock  and  key,  as  they 
are  dangerous  to  human  as  well  as  other  animal  life. 

The  utensils  employed  in  preparing  arsenical  mixtures  should 
be  thoroughly  cleansed  after  use. 

Lime  (oxid  of  calcium)  possesses  considerable  value  as  an 
insecticide  and  repellent,  its  efficiency  being  in  proportion  to  its 
dryness  and  caustic  quality.  It  is  more  effective  against  delicate 
and  moist  insects,  such  as  the  larvae  of  asparagus  and  potato 
beetles  and  root-maggots.  For  leaf-feeding  species  it  is  sifted 
on  the  plants  aqd  kills  by  contact,  literally  burning  holes  into 
the  soft  bodies  of  the  larvae  which  it  touches.  Certain  root- 
maggots  and  white  grubs  are  without  doubt  largely  attracted 
to  gardens  by  the  presence  of  manures  and  decomposing  veg- 
etable matter,  and  if  this  be  powdered  with  lime,  finely  sifted, 
it  soaks  into  the  material  with  rains  and,  moreover,  acts  as  a 
deterrent,  especially  against  the  flies  which  produce  the  root- 
maggots.     It  is  useful  also  for  slugs  or  snails. 

Fresh  air-slaked  or  quick  lime  should  be  used,  as  when  stale 
it  loses  its  caustic  properties. 

Gas  lime  is  of  value  in  clearing  infested  land  of  white  grubs 
before  planting  some  crops.  It  is  a  refuse  product  of  gas  plants 
and  may  be  obtained  frequently  merely  for  the  cost  of  hauling. 
It  contains  much  gas  in  a  crude  form,  and  to  be  of  greatest 
value  should  be  fresh  so  as  to  give  out  a  strong  gassy  odor  for 
several  days   after   application.  When   applied   to   lawns   it   is 


INSECTICIDES    AND    THEIR    USES  35 

sprinkled  over  the  surface  as  a  top  dressing.  In  fields  of  potato 
it  should  be  applied  between  rows  and  covered  by  earth,  by 
drilling  or  other  process,  as  there  is  a  possibility  of  injury  to 
plants,  and  this  method  should  be  used  experimentally  at  first. 
The  amount  to  use  will  vary  according  to  the  degree  of  infesta- 
tion by  white  grubs  and  other  conditions.  It  has  been  employed 
at  about  the  rate  of  4  barrels  to  100  square  feet  of  ground  on 
a  lawn  with  the  result  that  the  spring  after  application  all 
forms  of  vegetation,  including  weeds,  came  up,  and  only  five 
or  six  white  grubs  could  be  found.  In  Europe  gas  lime  has 
been  used  with  some  success  in  connection  with  other  remedies 
for  wireworms  at  the  rate  of  i>4  tons  to  the  acre. 

The  best  time  to  apply  the  lime  is  in  September,  after  the 
crop  is  made. 

Caution. — There  is  always  danger  to  plant  life  in  the  use 
of  gas  lime,  hence  before  employing  it  on  growing  crops  on  a 
large  scale  it  should  first  be  used  experimentally. 

Hellebore,  or  white  hellebore  (Veratrum  album)  is  less  dan- 
gerous than  the  arsenicals,  hence  has  some  votaries  for  its  use 
on  cabbage  and  other  plants  soon  to  be  eaten.  Its  use  is  open 
to  the  same  objection  as  pyrethrum  that  it  loses  its  insecticidal 
properties  by  exposure  to  the  air.  It  is  also  poisonous  to 
man  and  domestic  animals.  It  is  a  specific  against  the  slugs  or 
false-worms  (none  of  which  commonly  affect  vegetables),  which 
attack  raspberry,  currants  and  other  bush  fruits.  As  many  truck- 
growers  raise  bush  fruits  it  might  be  added  that  it  is  used  in 
both  dry  and  liquid  form,  but  can  be  applied  more-  thoroughly 
as  a  spray,  3/  ounce  of  powder  to  2  gallons  of  water.  Dr. 
James  Fletcher  recommends  its  employment  as  a  remedy  for 
certain  kinds  of  cabbage  pests,  including  "worms"  and  root- 
maggots.  On  the  latter  it  is  applied  at  the  rate  of  2  ounces  of 
powder  to  the  gallon  of  water,  and  applied  with  a  force-pump 
about  the  infested  roots. 


36  INSECTS    INJURIOUS   TO   VEGETABLES 

CONTACT   POISONS 

Kerosene  emulsion  is  the  standard  remedy  for  sucking 
insects  such  as  aphides  or  plant-lice,  plant-bugs  and  the  like, 
and  is  of  value  against  other  soft-bodied  insects,  which  cannot 
for  different  reasons  be  safely  poisoned  by  Paris  green  and 
similar  insecticides.  The  best  form  for  ordinary  use  is  the 
kerosene-soap  emulsion,  made  by  combining  2  gallons  of  kero- 
sene, Yz  pound  of  whale-oil  soap,  or  i  quart  of  soft  soap  with 
I  gallon  of  water. 

The  soap  should  be  dissolved  in  boiling  water  and  then  poured 
while  boiling  (away  from  the  fire)  into  the  kerosene.  The 
mixture  is  then  churned  violently  for  about  five  minutes  by 
means  of  a  force-pump  and  direct-discharge  nozzle  throwing 
a  strong  stream  by  pumping  the  liquid  back  upon  itself.  At  the 
end  of  this  time  the  mixture  will  have  become  of  the  con- 
sistency of  thick  cream.  Properly  prepared  an  emulsion  will 
keep  almost  indefinitely,  and  should  be  diluted  only  as  needed 
for  use.  For  most  insects,  except  scales,  the  staple  emulsion 
should  be  diluted  with  from  15  to  20  parts  of  water.  A  10  per 
cent,  solution,  or  even  stronger,  is  sometimes  necessary. 

In  the  preparation  of  kerosene  emulsion  a  force-pump  is  a 
necessity,  since,  if  not  made  according  to  directions,  a  perfect 
emulsion  is  not  formed.  There  is  then  danger  of  injury  to  the 
plants  by  the  kerosene,  as  also  useless  waste.  There  is  also 
danger  and  waste  if  the  insecticide  is  not  applied  by  means  of 
a  fine  nozzle  in  the  form  of  a  spray,  which  should  be  fine  and 
mist-like.  It  should  be  sprayed  only  long  enough  to  cover  the 
plants  and  not  so  that  the  liquid  forms  into  globules  and 
runs  off. 

In  the  practical  application  of  this  insecticide  certain  setbacks 
are  frequently  encountered.  One  of  these  is  due  to  the  fact 
that  aphides  and  many  other  sucking  insects  feed  more  or  less 
exclusively  on  the  under  surface  of  leaves,  which  necessitates 


INSECTICIDES   AND   THEIR   USES  37 

an  under-spraying  of  the  leaves  in  order  to  reach  the  pests.  This 
is  frequently  of  difficult  accomplishment  owing  to  the  thick 
growth  of  the  plants  after  they  have  got  well  started,  and  the 
fact  that  many  leaves  overlap  others.  An  example  of  the  dif- 
ficulty experienced  in  spraying  for  aphides  is  afforded  in  the 
pea  aphis,  particularly  where  peas  are  grown  broadcast,  which 
does  not  permit  the  driving  of  a  machine  through  the  fields. 
The  leaves  interlace  and  intertwine  in  such  a  manner  that  the 
insects  cannot  be  reached.  The  same  is  the  case  with  melons 
after  they  have  attained  any  growth.  There  is  also  danger  of 
injury  to  the  vines  by  the  wagon  wheels  and  the  horse  in  going 
through  the  fields. 

For  success  with  this  remedy  it  is  in  many  cases  absolutely 
necessary  that  the  emulsion  should  be  applied  so  that  it  will 
actually  come  in  contact  with  or  strike  the  insects  against  which 
it  is  directed. 

Kcroscnc-milk  emulsion  is  sometimes  used,  but  it  is  hardly 
as  satisfactory  as  kerosene-soap  emulsion,  since  the  soap  in  the 
latter  has  also  considerable  killing  and  repelling  power. 

Carbolic-acid  emulsion. — For  some  purposes  it  is  desirable  to 
add  to  kerosene  emulsion  a  quantity  of  carbolic  acid,  e.  g.,  for 
the  treatment  of  various  root-infesting  insects,  such  as  root- 
maggots  affecting  seed-corn,  onion,  and  cabbage.  This  emulsion 
is  prepared  at  the  rate  of  i  pound  of  soap,  I  gallon  of  water, 
and  Yz  gallon  of  crude  carbolic  acid,  and  is  diluted  with  from 
35  to  50  parts  of  water.  It  has  been  found  quite  effective 
against  root-maggots,  the  plants  showing  no  injury  due  to  the 
insecticide.  It  should  be  applied  a  day  or  two  after  the  plants 
are  up,  or,  in  case  of  crops  that  are  transplanted,  the  day;  after 
they  are  set  in  the  field,  and  should  be  repeated  every  ;week  or 
ten  days  until  about  the  latter  half  of  May.  Carbolic  acid  is 
at  once  a  repellent  and  a  contact  and  stomach  poison.  It  should 
be  handled  with  care  as- it  is  corrosive! 

Corrosive  sublimate   (Bichlorid  of  mercury)    is  prepared  by 


38  INSECTS    INJURIOUS   TO   VECIETABLES 

mixing  2  to  2^  ounces  of  the  poison  with  15  gallons  of  water. 
The  poison  is  first  dissolved  in  2  gallons  of  water,  and  more 
is  added  to  make  15  gallons.  This  is  allowed  to  stand  5  or  6 
hours,  and  the  solution  agitated  several  times.  This  is  a  fun- 
gicide as  well  as  insecticide,  and  is  useful  both  for  potato  scab 
and  the  potato  scab  gnat.  Seed  potatoes  are  soaked  from  an 
hour  and  a  half  to  three  hours  in  this  solution  before  planting. 
As  corrosive  sublimate  is  a  violent  poison,  unusual  care  should 
be  exercised  in  handling  it.  It  should  not  be  mixed  in  metallic 
vessels,  nor  exposed  where  it  might  be  eaten  by  stock. 

Formalin  is  prepared  by  mixing  8  ounces  of  40  per  cent, 
solution  with  15  gallons  of  water,  and  is  used  for  the  same 
purposes  as  corrosive  sublimate,  but  is  less  poisonous.  Seed 
potatoes  are  immersed  two  hours. 

Soap  preparations.— Sosip  solutions  are  valuable  as  washes  in 
the  control  of  noxious  insects.  Both  hard  and  soft  soaps  are 
used,  but  "whale-oil"  soaps,  usually  manufactured  of  fish-oil, 
are  of  greatest  value.  A  solution  of  fish-oil  soap  is  prepared 
by  dissolving  I  pound  of  the  soap  in  from  4  to  10  gallons  of 
water.  On  some  hardy  plants  a  strength  of  i  pound  of  soap 
to  2  gallons  of  water  can  be  used,  but  this  is  harmful  to  delicate 
plants  and  must  be  employed  with  caution.  A  wash  of  i  pound 
soap  to  6  or  8  gallons  is  of  most  value  for  aphides,  minute  leaf- 
bugs,  leafhoppers,  and  thrips,  and  some  forms  of  small  larvas. 
These  soaps  possess  no  particular  advantage,  however,  over 
kerosene-soap  emulsion  and  are,  in  fact,  less  effective  against 
vegetable-feeders.  Castile  or  "neutral"  soaps,  among  which  are 
ivory  soap,  are  much  used  on  plants  grown  under  glass  and  as 
a  means  of  arresting  the  ravages  of  "red  spider"  and  the  same 
insects  that  have  been  mentioned. 

Cold  and  hot  zvater  are  properly  speaking  contact  insecticides 
of  value  in  the  destruction  of  minute  insects  such  as  aphides. 
A  strong  spray  of  ice  cold  water  applied  to  louse-infested  plants 
is  a  very  useful  remedy,  but  hot  water  is  still  more  effectual 


INSECTICIDES   AND   THEIR    USES  39 

as  a  means  of  riddance  of  these  pests.  The  latter  is  most  ap- 
plicable to  such  plants  as  cabbage,  which  withstands  a  high 
degree  of  temperature,  which  would  be  hurtful  to  less  hardy- 
plants.  A  water  thermometer  is  employed,  and  care  is  observed 
that  the  temperature  does  not  reach  far  above  150°,  the 
scalding  point  for  most  plants.  From  125  to  135°  is  sufficient 
for  the  destruction  of  most  insects,  but  applied  still  hotter  where 
possible  is  still  more  effective.  Cabbage  will  withstand  a  tem- 
perature of  180°  without  special  harm.  When  setting  out  cab- 
bage and  some  other  plants  they  can  be  freed  from  "lice"  by 
dipping  them  into  water  heated  to  between  125  and  150°.  Hot 
water  cannot  be  thrown  in  a  spray  owing  to  its  cooling  too 
rapidly,  and  it  is  necessary  if  it  is  to  be  thoroughly  effectual 
for  it  to  actually  strike  the  insects  which  it  is  desired  to  destroy. 
Where  only  a  few  plants  are  to  be  protected  and  it  is  possible 
to  reach  the  "lice"  with  water  applied  with  a  garden  hose, 
syringe  or  spraying  machine  their  work  can  be  checked.  Such 
as  come  in  direct  contact  with  a  stiif  spray  at  an  ordinary 
temperature  are  unable  to  survive,  while  many  that  are  dis- 
lodged cannot  return  to  the  plants  as  most  of  them  are  wingless 
and  unable  to  crawl  any  distance,  particularly  if  the  ground  be 
dry  and  hot. 

INSECTICIDES    WHICH    KILL   BY    SUFFOCATION 

Under  this  caption  will  be  included  insecticides  which  do  not 
properly  fall  under  the  heading  of  either  stomach  or  contact 
poisons.  Of  these  are  pyrethrum ;  tobacco,  which  acts  both  as 
a  repellent  and,  when  vaporized,  as  a  destroyer  of  aphides  and 
thrips ;  bisulphid  of  carbon  and  hydrocyanic-acid  gas,  two  deadly 
gases,  and  some  others. 

Pyrethrum.— St\^r?i\  forms  of  insect  powder,  the  pulverized 
dry  flowers  of  different  forms  of  daisies,  are  on  the  market 
under  such  names  as  Persian  and  Dalmatian  insect  powder. 
One    of   these    is    buhach,    made    exclusively    from    Pyrethrum 


40  INSECTS    INJURIOUS    TO   VEGETABLES 

cineraricefolium.  It  was  carefully  tested  years  ago  by  the  De- 
partment of  Agriculture  at  Washington,  and  although  not  use- 
ful against  all  forms  of  insects,  is  very  valuable  for  household 
pests,  aphides,  and  small  plant-bugs  and  caterpillars.  It  is  best 
used  dry  by  dusting  the  plants  affected  with  an  insufflator  or 
bellows  while  wet  with  dew.  It  acts  by  closing  the  breathing 
pores  of  the  insects,  and  has  the  advantage  of  being  harmless 
to  man  and  the  higher  animals.  It  is  also  used  in  liquid  form, 
as  a  spray,  the  buhach  being  first  mixed  with  enough  water  to 
make  a  thin  paste  and  allowed  to  stand  about  two  hours,  after 
which  more  water  is  added  to  bring  it  to  the  desired  strength, 
the  usual  proportions  being:  2  ounces  to  5  gallons  of  water. 
An  alcoholic  decoction  is  also  sometimes  used. 

Under  different  trade  names,  pyrethrum  is  placed  on  the 
market  in  hermetically  sealed  tin  cans,  so  that  it  retains  its  full 
strength  until  used.  Powders  that  are  not  packed  in  tightly 
sealed  cans  lose  their  strength,  and  are  therefore  less  effective. 
In  small  lots  pyrethrum  costs  10  cents  an  ounce;  if  six  pounds 
are  purchased  it  can  be  had  for  about  50  cents  a  pound. 

Tobacco  is  an  old-time  remedy  for  many  insects,  and  still  in 
vogue  among  a  certain  class  of  farmers  and  florists,  but  in 
recent  years  it  has  been  largely  replaced  by  other  and  more 
approved  insecticides,  such  as  Paris  green  and  kerosene  emul- 
sion, and  in  greenhouses  by  the  hydrocyanic-acid  gas  process. 
The  method  of  its  application  varies  according  to  the  crop  af- 
fected and  the  insect.  Where  tobacco  stems  and  other  refuse 
can  be  easily  obtained  from  the  factories  it  is  advisable  to  use 
it  as  a  protection  against  certain  species  of  insects. 

For  the  striped  cucumber  beetle  and  melon  aphis,  it  is  used 
by  sprinkling  the  hills,  particularly  when  the  soil  is  moist,  with 
refuse  dust.  Thus  used  it  has  the  advantage  of  acting  as  a 
fertilizer  and  mulch  for  the  plant,  as  well  as  being  a  repellent 
to  the  beetle  and  other  insects.  Applications  must  be  repeated 
after  rainfall. 


INSECTICIDES    AND   THEIR   USES  4I 

Nicotine  extracts  and  pozvdcrs  are  extensively  used  by  florists 
as  general  fumigants  for  aphides,  thrips,  white  fly,  and  other 
small  and  soft-bodied  insects  in  greenhouses.  These  extracts 
are  manufactured  by  a  number  of  firms  who  advertise  chiefly 
in  florists'  journals.  They  contain  a  much  larger  proportion 
of  nicotine  than  decoctions,  and  are  proportionately  more  ef- 
fective. They  are  used  in  various  ways :  Dry  fumigants  are 
placed  in  shallow  pans  and  a  few  drops  of  kerosene  poured  on 
to  facilitate  ignition.  These  burn  slowly,  producing  a  smudge 
which  is  fatal  to  aphides  and  similar  insects.  The  liquid  prep- 
arations are  evaporated  over  an  alcohol  lamp,  or  are  "painted" 
on  steam  pipes,  or  hot  irons  are  put  into  the  receptacles. 

The  amount  of  nicotine  solution  to  use  depends  upon  its 
strength  (varying  from  about  35  to  85  per  cent,  nicotine),  the 
plants  to  be  treated,  the  size  of  the  frames  or  greenhouse  and 
the  construction  of  the  latter,  whether  tight  or  loose.  A  pre- 
liminary test,  on  a  small  scale,  is  therefore  a  prerequisite  to  the 
use  of  a  nicotine  fumigant.  Follow  the  directions  accom- 
panying the  preparation  used  and  increase  or  decrease  the 
strength  as  necessary.  If  cucumbers  are  being  fumigated,  a 
smaller  amount  may  be  desirable.  One  of  the  most  widely 
known  of  these  nicotine  solutions  has  been  used  with  great  suc- 
cess at  the  rate  of  5  or  6  teaspoonfuls  of  the  liquid  to  8  quarts 
of  water  vaporized  in  5.000  cubic  feet  of  greenhouse  space. 
Used  thus  on  cucumbers  at  night  it  did  not  injure  the  plants, 
while  thrips  which  infested  the  plants  were  killed.  Aphides 
are  more  easily  killed  than  thrips,  while  white  flies  require  still 
longer  exposure  and  repeated  applications. 

After  treatment  plants  are  carefully  syringed  with  whale-oil 
or  similar  soap  and  the  house  ventilated.  A  second  fumigation 
is  sometimes  given,  allowing  the  tobacco  smudge  to  remain  over 
night.  A  surplus  of  moisture  is  to  be  avoided,  as  it  induces 
spot,  mildew,  and  similar  fungous  diseases. 

Sulphur,  applied  dry  in  the  form  of  "flowers  of  sulphur,"  is 


42  INSECTS    INjURIOLS   TO    N'EGKTAHLES 

a  veritable  specific  for  "red  spider"  on  certain  plants  grown 
under  glass.  It  is  also  applied  dry  mixed  with  an  equal  bulk 
of  air-slaked  lime,  and  by  means  of  a  powder  bellows.  It  is 
also  used  in  conjunction  with  kerosene  emulsion  or  soap  washes, 
added  in  the  proportion  of  i  to  2  pounds  to  50  gallons  of  the 
spraying  solution.  It  is  first  mixed  into  a  paste.  As  a  vapor 
it  is  exceedingly  harmful  to  plant  life,  hence  should  not  be  used 
as  a  fumigant  in  forcing  houses  or  in  a  confined  structure. 

Bisulphid  of  carbon  {CS-,) ,  a  specific  against  insects  affecting 
stored  grain  and  other  products,  has  a  special  value  in  the  treat- 
ment of  some  forms  of  insects  afTecting  vegetable  crops,  more 
particularly  aphides,  and  root-feeding  insects,  such  as  root-mag- 
gots of  cabbage  and  onion.  This  reagent,  when  pure,  is  a  color- 
less liquid  and  has  a  powerful  and  disagreeable  odor;  it  vapor- 
izes rapidly  when  exposed  to  the  air,  is  highly  inflammable  but 
not  explosive,  and  is  deadly  to  all  forms  of  animals,  including 
human  beings.  Its  field  of  usefulness  is  among  such  insects  as 
we  cannot  reach  with  poisons  by  direct  contact  or  through  their 
foods. 

The  method  of  applying  bisulphid  of  carbon  varies  according 
to  the  nature  of  the  plants  affected  and  the  insects  to  be  de- 
stroyed. The  method  of  treating  the  melon  aphis  and  root- 
maggots  will  be  described  in  the  consideration  of  those  insects. 


PROPRIETARY    INSECTICIDES 

Numerous  proprietary  insect  destroyers  are  on  the  market, 
and  their  number  is  increasing.  Analyses  of  these  are  being 
made,  with  the  result  that  although  a  few  are  not  without  value 
they  are  as  a  whole  decidedly  inferior  to  approved  combinations 
advised  by  entomologists,  of  the  character  that  are  mentioned 
in  preceding  pages ;  in  fact,  they  occupy  the  same  relation  to 
standard  insecticides  that  quack  nostrums  do  to  the  prescrip- 
tions of  reliable  physicians,  or  preparation  of  recognized  value 


INSECTICIDES    AND    THEIR    L'SES  43 

and  known  composition.'  Among  proprietary  insecticides  that 
have  been  reported  to  be  found  by  analysis  of  little  or  no  value 
or  too  costly  are  those  bearing  names  suggestive  of  "sure  pop," 
"bug  shot,"  "certain  death,"  "kill-em-quick,"  and  certain  lice 
and  "vermin"  exterminators,  roach  destroyers,  etc. 

On  this  head  it  is  advised  that  in  view  of  the  fact  that  so 
many  proprietary  insecticides  are  either  fraudulent  or  extremely 
expensive,  considering  the  value  of  their  ingredients,  it  would 
be  well  to  make  sure  of  the  composition  and  value  of  each 
before  purchasing. 

Among  the  most  useful  proprietary  remedies  are  nicotine  solu- 
tions or  tobacco  extracts  and  powders  which  are  not  mixtures 
or  nostrums,  but  just  what  their  manufacturers  claim  for  them. 

INSECTICIDE    APPARATUS 

In  the  application  of  insecticides  different  types  of  apparatus 
are  necessary,  according  to  whether  the  material  used  is  to  be 
applied  dry  in  powder  or  as  a  spray.  The  types  necessary  for 
the  former  are  simple,  the  spraying  devices  are  numerous  and 
many  efficient  sprayers  and  like  mechanisms  are  on  the  market. 

For  dry  application,  such  as  pyrethrum,  sulphur,  and  Paris 
green  mixed  with  flour,  powder  bellows  or  atomizers  costing 
about  $2  are  much  used,  particularly  for  gardens  or  where  small 
areas  in  larger  fields  are  infested. 

For  spraying. — No  stronger  evidence  of  the  progress  in 
economic  entomology  could  be  cited  than  the  number  of  firms 
engaged  in  the  manufacture  and  sale  of  spraying  apparatus. 

Such  crude  mechanisms  as  are  for  sale  at  from  75  cents  to 
$2  or  $3,  both  under  the  title  of  syringes  and  sprayers,  can 
scarcely  be  recommended  for  up-to-date  work.  They  do  not,  as 
a  rule,  produce  a  true  spray ;  they  are  too  apt  to  get  out  of 

^  Such  as  paregoric,  Rochelle  salts,  Seidlitz  powders,  and  various  extracts, 
elixirs,    tinctures,    mixtures,    solutions,    anodynes,    etc. 


44 


INSECTS    INJURIOUS   TO   VEGETABLES 


order  and  therefore  do  not  last  longer  than  a  season  or  two. 
The  want  of  an  instrument  to  fulfill  modern  requirements  for 
a  Hue  spray  is  met  by  various  manufacturers  in  the  form  of 
knapsack  sprayers,  bucket  pumps  and  barrel  spray  pumps. 

The  spray  is  obtained  by  a  hose  attachment  and  different 
forms  of  nozzles,  of  which  the  vermorel  type  is  the  best. 

The  knapsack  sprayer  is  a  copper  tank  made  to  be  strapped 


Fig.  22.— Knapsack  sprayer 

on  the  back  of  the  operator  (fig.  22).  Within  there  is  a  small 
pump  which  is  operated  with  one  hand  while  the  nozzle  is  held 
in  the  other.  The  handle  may  be  removed,  if  desired,  and  the 
tank  carried  by  hand  instead  of  on  the  back.  The  cost  is  from 
$9  to  $18.  It  is  good  for  gardens  and  for  moderate-sizfed  plats 
on  truck  farms.  Of  its  usefulness  Mr.  M.  B.  Waite,  a 
pathologist  of  the  United  States  Department  of  Agriculture, 
says  in  substance : 

The  barrel  pump  has  nearly  driven  out  the  knapsack  outfit 


INSECTICIDES   AND   THEIR   USES 


45 


in  commercial  operations.  In  spraying  several  acres  of  can- 
taloupes once  the  writer  was  surprised  to  find  that  a  man  with 
a  knapsack  outfit  could  do  the  work  at  the  same  price  as  an 
outfit  consisting  of  a  barrel  mounted  on  a  sled  drawn  by  a  horse 
and  operated  by  three  men,  one  to  pump  and  drive  and  two  to 
carry  the  nozzles.  The  latter  outfit, 
however,  got  over  the  ground  so  much 
more  rapidly  and  saved  so  much  time 
that  it  was  mainly  used.  The  objec- 
tions to  the  knapsack  pumps  are 
numerous.  It  is  hard  to  get  the  re- 
quired pressure  in  the  pump  on  account 
of  its  small  size  and  instability.  It  is 
rather  heavy  to  carry  on  the  back  and 
is  very  liable  to  leak,  and  the  oper- 
ator who  can  handle  one  all  day  with- 
out getting  his  back  wet  and  some  of 
the  liquid  down  his  neck  is  fortunate. 
As  a  rule,  the  low  pressure  obtained 
by  the  knapsack  pump  results  in  an 
inferior  job  of  spraying,  though  with 
a  strictly  first-class  vermorel  nozzle  this  is  not  necessarily  so. 

Bucket  pumps. — Good  hand  bucket  spray  pumps  of  about  the 
type  shown  in  figure  23  may  be  had  at  from  $6  to  $7.50.  They 
are  of  great  value  in  the  preparation  of  kerosene  emulsion, 
which,  as  has  already  been  stated  (p.  36),  should  be  applied  as 
a  fine  mist-like  spray.  They  may  be  used  with  ordinary  or 
special  buckets  and  a  longer  hose  than  figured  (fig.  23)  and 
may  be  necessary. 

Barrel  spray  pumps. — These  are  the  largest  force  pumps  and 
useful  both  for  the  field  and  orchard.  They  are  mounted  on 
barrels  or  tanks  and  drawn  for  field  and  garden  use  on  wheels, 
so  geared  as  to  straddle  rows  of  vegetables,  or  a  narrow  sled 
may  be  made  to  serve  the  same  purpose.    A  serviceable  sled  may 


Fig.  23.— Hand  bucket  pump 


INSECTS    INJURIOUS   TO   VEGETABLES 


Fig-  23x.— Hand  barrel  spray  with  cart  in  operation  i 
(After  Orton,  U  S.  Dept.  Agr.) 


.  cucumber  field 


be  made  by  fastening  planks  across  two  pieces  2  or  3  x  4  inches 
and  with  rounded  ends  for  runners.  Two-wheeled  carts  may 
also  be  used  for  such  an  outfit.  Such  a  one  designed  for  spray- 
ing four  rows  of  plants  and  from  two  sides  at  once  is  used  by 
Prof.  F.  L.  Washburn  of  the  Minnesota  Experiment  Station 
(fig.  24). 


Fig.  24-— A  four-rgw  sprayer-     (After  Washburn) 


INSECTICIDES    AND   THEIR    USES 

Noz::;les. — One  of  the  main  causes  of  failure 
on  the  part  of  farmers  to  obtain  good  results 
from  spraying  is  the  use  of  inferior  nozzles  which 
are  too  often  supplied  by  dealers.  The  ver- 
morel  type  (fig.  24X),  for  sale  (single)  at  about 
$1.25,  is  the  best,  having  stood  the  test  of  25 
years  and  more  of  use. 


Fig.  24x.-Ver- 
morel  nozzle 


REMARKS    ON    APPLYING  INSECTICIDES 

In  the  application  of  remedies  12  points  are  selected  as  im- 
portant to  be  observed : 

1.  Be  sure  of  the  insect  which  is  the  primary  cause  of  the 
damage. 

2.  Make  certain  that  the  best  remedy  or  remedies  are  used. 

3.  When  an  insecticide  is  employed,  ascertain  if  .it  is  of 
standard  quality,  because  if  it  is  lacking  in  strength  it  will  fail 
of  its  purpose.  If  not  diluted  according  to  directions,  and  if 
therefore  too  strong,  there  is  danger  of  scalding  or  otherwise 
injuring  the  plants. 

4.  The  preparation  used  should  be  properly  prepared.  Thus 
if  kerosene  emulsion  is  the  remedy,  it  should  be  a  true  emulsion 
and  not  a  mere  mixture  of  water,  soap  and  kerosene. 

5.  The  best  insecticide  apparatus  for  the  purpose  for  which 
it  is  designed  should  be  obtained,  and  for  vegetables  it  is  nec- 
essary in  most  cases  that  a  sprayer  be  used,  and  as  often  as  not 
the  spray  must  be  applied  so  as  to  reach  the  under  surface  of 
the  leaves,  and  remain  on  them  and  not  roll  ofif. 

6.  The  smallest  amount  of  poison  should  be  used  to  produce 
the  desired  result ;  much  poison  is  wasted  by  persons  who  do  not 
understand  its  proper  application. 

7.  Remedies  should  be  applied  at  the  right  time,  usually 
when  the  insect  first  appears;  as,  for  example,  when  a  cater- 
pillar has  just  hatched  from  the  &gg,  or  when  a  beetle  begins 
to  come  out  from  winter  retreats  in  search  of  food.     Inex- 


48  INSECTS    INJURIOUS   TO   VEGETABLES 

perienced  persons  apply  for  information  after  the  principal 
damage  is  done,  and  before  an  answer  in  regard  to  remedial 
treatment  can  be  received  it  is  too  late  to  apply  remedies. 
In  the  treatment  of  insects  which  may  always  be  expected,  for 
example  the  striped  cucumber  beetle,  preparation  should  be 
made  before  the  appearance  of  the  pest. 

8.  In  the  case  of  many  insects  it  is  visually  necessary  to 
apply  remedies  more  than  once,  sometimes  three  or  four  times, 
according  to  the  number  of  generations  of  the  insects,  and 
whether  severe  rains  have  intervened  to  wash  away  applications 
before  the  insects  have  fed  upon  them. 

9.  If  injury  is  severe  it  is  often  desirable  to  apply  remedies 
for  other  insects  and  diseases  which  may  be  present,  as  other- 
wise the  crop  may  be  ruined,  though  the  primary  cause  be  re- 
moved. Fertilizers  are  often  advisable  to  stimulate  plants  and 
enable  the  production  of  a  crop  in  spite  of  insect  injury. 

ID.  Clean  methods  of  farming  are  of  more  value  in  preventing 
injury  than  any  other  method  that  can  be  named,  and  if  it  were 
more  generally  observed  insect  injury  would  soon  be  very  mate- 
rially reduced. 

11.  The  cooperation  of  one's  immediate  neighbors  is  very 
desirable  in  the  treatment  of  many  insects,  particularly  tliose 
which  are  not  free-flying. 

12.  The  timely  application  of  a  remedy  acts  as  a  preventive. 


CHAPTER   V 


GENERAL  CROP  PESTS 

Injurious  insects  may  be  classified,  as  regards  the  nature  of 
their  food  plants,  into  several  more  or  less  distinct  groups. 

The  most  important  of  these  are  choice  or  special  feeders, 
and  include  many  of  our  worst  pests.  They  attack  only  single 
crops  or  crops  of  a  single  class,  save  in  the  direst  necessity 
when  they  sometimes  resort  to  other  crops  and  weeds.  Examples 
of  this  group  are  the  two  asparagus  beetles  which  live  exclu- 
sively on  asparagus,  the  cotton  worm  and  boll  weevil,  which  are 
injurious  only  to  cotton,  and  the  tobacco  worms  which  affect 
only  tobacco,  tomato  and  plants  of  the  same  botanical   family. 

Many  insects  are  more  or  less  nearly  omnivorous.  Although 
some  have  favorite  host  plants,  they  are  likely  to  attack  many 
other  plants,  and  when  extremely  numerous  or  when  the  favored 
food  becomes  scarce  they  devour  nearly  every  form  of  vegeta- 
tion that  grows  in  the  garden,  field,  orchard  or  forest.  This 
group  is  not  so  numerous  as  the  first  and  not  so  destructive,  as 
a  rule,  because  of  attack  being  distributed,  but  certain  cutworms 
and  other  caterpillars,  leaf-beetles,  flea-beetles,  aphides  and 
others  may  do  very  serious  damage,  while  still  others,  like 
locusts  and  army  worms,  sweep  over  large  areas  and  in  a  short 
time  ruin  entire  crops. 

CUTWORMS    AND    RELATED    INSECTS 

Cutworms  are  among  the  most  troublesome  insects  with  which 
the  market  gardener  has  to  deal.  They  are  familiar  to  most 
persons,  and  sooner  or  later  everyone  engaged  in  plant  growing 
has  to  contend  with  these  pests,  for  they  are  what  are  termed 

49 


so  INSECTS    INJURIOUS    TO    VEGETABLES 

"general  feeders,"  and  able  to  eke  out  a  living  wherever  they 
may  be.  Thus  it  happens  that  they  are  to  be  found  in  most 
gardens  and  nearly  everywhere  else,  in  pasture  land,  vineyards, 
fields  and  orchards,  and  even  in  greenhouses. 

The  species  are  very  numerous,  and  many  of  them,  like  white 
grubs  and  wireworms,  were  the  original  inhabitants  of  the  soil 
of  this  country,  but  some  have  been  supplanted  in  injuriousness 
by  species  introduced  from  abroad.  Taken  as  a  class,  cutworms 
rank  with  such  insects  as  the  San  Jose  scale,  Hessian  fly,  the 
chinch-bug,  and  others  of  our  worst  pests. 

When  conditions  favor  the  multiplication  of  cutworms  they 
will  feed  upon  anything  green  and  succulent,  whether  foliage, 
flowers,  buds,  fruit,  stalks,  tubers,  or  roots.  Although  nearly 
ubiquitous,  they  are  more  especially  destructive  in  truck  gar- 
dens, and  young,  tender  plants  when  first  set  out,  such  as 
tomatoes,  cabbage,  and  plants  just  appearing  above  the  soil, 
such  as  potatoes  and  corn,  suffer  most  seriously.  Several  are 
destructive  to  foliage  of  fruit  trees,  and  from  their  habit  of 
climbing,  are  known  as  climbing  cutworms;  while  in  years  of 
unusual  abundance,  some  assume  the  army  worm  habit. 

Cutworms  are  the  progeny  of  owlet  moths  (fig.  27,  c),  and  are 
nocturnal,  remaining  hidden  during  the  day  to  come  forth  at 
night,  the  moths  to  mate  and  deposit  their  eggs,  the  cutworms 
to  feast  upon  whatever  happens  to  be  most  available  and 
palatable. 

There  are  so  many  species  of  injurious  cutworms — between 
two  or  three  score — that  it  is  impossible  to  give  a  description 
that  would  fit  all,  but  most  common  species  are  robust,  soft- 
bodied,  smooth  or  nearly  smooth,  cylindrical  caterpillars,  varying 
in  color  from  pale  whitish  or  dirty  gray  (like  fig.  28,  a),  to  near- 
ly black,  many  being  more  or  less  plainly  striped  or  spotted,  as 
is  the  case  with  the  w-marked  cutworm  shown  in  figure  25. 

They  seldom  attract  attention  except  in  early  spring,  and 
then    experienced    persons    can   only   too    readily   detect    their 


GENERAL    CROP    PESTS  5 I 

presence  by  finding  young  plants  with  tender  stems  that  have 
just  been  set  out,  cut  off  near  the  surface  of  the  ground.  The 
culprit  rests  in  a  curved  position  during  the  day  concealed  in 
the  earth  around  the  plants  which  it  has  destroyed  during  the 
previous  night.  Some  species  leave  open 
holes  where  they  have  buried  themselves 
in  the  earth,  others  seek  shelter  under 
any  debris,  such  as  old  boards,  stones 
or  dead  leaves,  and  a  few  species  have  pig.  25.-w-markedcutworm 
a  habit  of  dragging  portions  of  plants  (Noctua  danaestma) 

which   they   have   cut   off  to   their   sub-  '  ^^ 

terranean  retreats  where  they  can  feed  at  leisure. 

Most  species  are  single-brooded  northward,  but  many  produce 
two  or  more  generations  southward. 

The  greatest  injury,  as  previously  stated,  is  done  in  early 
spring  for  the  following  reasons:  The  last-appearing  genera- 
tion of  moths  issue  from  the  ground  in  midsummer  or  autumn, 
and  deposit  eggs  from  which  larvae  hatch  and  feed  until  cold 
weather  drives  them  to  their  winter  quarters.  A  considerable 
proportion  of  such  larvae  are  from  half  to  three-quarters  grown, 
and  in  this  condition  many  hibernate,  although  a  few  species 
pass  the  winter  in  the  pupal  condition  and  less  exceptionally 
as  moths.  The  eggs  are  deposited,  often  in  large  masses,  on 
such  growth,  grasses  and  weeds  as  spring  up  after  a  crop  has 
been  harvested,  and  when  this  is  plowed  under  to  make  room 
for  the  new  crop  that  is  planted  in  spring,  comparatively  few 
plants  come  up,  and  as  a  result,  the  immature  cutworms  are 
forced  to  feed  upon  whatever  is  available.  This  explains  their 
great  destructiveness,  as  it  is  a  matter  of  yearly  occurrence  in 
many  neighborhoods  for  cutworms  to  destroy  large  portions 
of  a  planting  and  even  entire  crops,  necessitating  replanting 
sometimes  a  third  or  fourth  time  before  a  good  stand  can  be 
obtained. 

The  life  histories  of  cutworms  vary  according  to  the  species 


52 


INSECTS    INJURIOUS   TO   VEGETABLES 


and  the  locality  which  each  inhabits ;  hence  little  that  is  really 
typical  of  the  group  can  be  spoken  of  in  general  terms.  After 
cutworms  have  accomplished  their  customary  injuries  in  the 
spring  and  have  attained  full  growth,  they  enter  the  earth,  and 
many  species  remain  in  little,  rather  compact  earthen  cells 
(fig.  26)  for  several  weeks  or  even 
months  before  assuming  the  pupal 
stage,  which  is  of  variable  duration 
in  th^!  summer,  from  three  to  six  or 
more  weeks  before  the  moths  is- 
sue to  perform  the  functions  of 
their  nature. 

The  Greasy  Cutworm  (Agrotis  ypsilon  Rott.)  is  typical  as 
regards  its  general  appearance  and  is  abundant  in  most  localities 
suitable  to  it.     It  is  one  of  our  larger  species,  measuring  when 


Fig-  26. — Pupa  of  cutworm  in 
earthen  cell.     (After  Riley) 


6 

Fig.  27.— Greasy  cutworm,  a.  Larva;  b,  head  of  same; 
c,  moth.  Natural  size.  (After  Riley  &  Howard, 
U.  S.  Dept.  Agr.) 

mature  about  one  inch  and  three-fourths.  It  is  of  the  dull, 
dirty  brown  color,  characteristic  of  so  many  cutworms,  with  the 
lower  surface  paler  and  greenish.  The  moth  (fig.  2y,  c)  has 
brown  fore-wings  marked  with  darker  brown,  more  or  less  like 


GENERAL    CROP    PESTS  53 

the  Specimen  figured,  and  with  an  average  expanse  of  an  inch 
and  three-fourths.  It  is  a  cosmopoHte.  This  cutworm  has  a 
most  pernicious  cutting  habit.  It  will  sever  large  tomato  plants 
over  six  inches  in  height  generally  at  an  inch  above  ground, 
and  after  destroying  one  plant  it  travels  to  others  and  thus  in 
a  night  a  single  worm  ruins  three  or   four  plants.     It   shows 


Fig.  28.— Granulated  cutworm-    a.  Larva;  /,  moth 
Natural  size.     (After  Riley) 

some  partiality  for  cabbage  which  it  frequently  devours  as  fast 
as  transplanted.  Potato,  corn,  lettuce  and  tobacco  are  favored, 
while  ornamental  flowering  plants  are  not  exempt.  Of  many 
plants  it  eats  leaves  and  roots.  It  is  probable  that  this  species 
is  double-brooded  or  has  a  dual  method  of  hibernation. 

The  Granulated  Cutworm  (Fcltia  anncxa  Treitsk.)  (fig.  28) 
is  brownish  gray  and  similar  to  the  greasy  cutworm,  but  lacks 
the  greasy  appearance,  and  may  be  recognized  by  the  character 
which  has  suggested  its  English  name.  The  entire  surface  of 
the  body,  as  viewed  with  a  magnifier,  is  seen  to  be  closely 
covered  with  very  small,  round,  blackish  granules,  each  bearing 
a  minute  sharp  point.  The  length,  when  full  grown,  is  about 
an  inch  and  one-half. 

The  Variegated  Cutworm  (Pcridroma  saucia  Hub.). — This 
Is  with  little  doubt  the  most  destructive  and  widely  known  of 
all  cutworms.  It  occurs  nearly  everywhere  and  although,  like 
others  of  its  kind,  it  appears  to  favor  garden  plants,  it  will 


54 


INSECTS    INJURIOUS   TO   VEGETABLES 


attack  nearly  any  form  of  vegetation,  feeding  on  all  parts  of 
plants  when  it  occurs  in  numbers.  It  is  a  climbing  cutworm, 
and  when  exceptionally  abundant,  assumes  the  army  worm 
habit.  Its  progenitor  is  a  large  moth  (fig.  29,  a)  with  pale, 
grayish-brown  fore-wings  tinged  with  reddish  and  shaded  with 


Fig.  29.— Variegated  cutworm  (Peridroma  saucia).  a.  Moth; 
.  b,  larva,  lateral  view;  c,  same  coiled  up;  d,  dark  form,  dorsal 
view.    (After  Howard,  U.  S.  Depi.  Agr.) 

darker  brown.  There  is  considerable  variability  in  markings, 
which  are  often  suffused.  The  same  holds  of  the  cutworm  itself 
(fig.  29,  c,  d).  At  maturity  this  cutworm  measures  about  one 
and  three-fourths  inches.  The  variegated  cutworm  is  cosmo- 
politan in  the  broadest  sense  of  the  word,  and  is  injurious 
throughout  practically  all  arable  regions. 

METHODS    OF    CONTROL 

Poisoned  baits  are  the  standard  remedies  against  cutworms. 
To  be  effective  they  should  be  applied  as  soon  as  attack  is 
noticed  and  are  particularly  valuable  in  cases  where  the  direct 
application  of  poisons  is  impossible  owing  to  the  danger  of 
poisoning  persons  or  stock  when  it  is  used  for  food.  There  are 
two  kinds  of  bait — fresh  vegetable  and  bran  mash. 

Vegetable  bait. — Vegetable  bait  may  be  prepared  by  spraying 


GENERAL  CROP  PESTS  55 

a  patch  of  clover,  or  useless  succulent  plant  with  Paris  green, 
I  pound  to  150  gallons  of  water;  mowing  it  close  to  the  ground, 
and  placing  it  while  fresh  in  small  heaps  about  infested  plants 
at  intervals  of  a  few  feet.  Owing  to  the  wilting  of  this  bait, 
in  dry,  sunny  weather,  it  is  advisable  to  cover  each  heap  with 
a  chip,  shingle,  or  something  similar. 

Bran  mash  or  bran-arsenic  mash  is,  according  to  some,  still 
more  efficacious.  Paris  green,  white  arsenic,  or  other  arsenical 
can  be  used  for  poisoning,  and  in  its  preparation,  on  account 
of  the  weight  of  the  poison  and  the  fact  that  it  soon  sinks  when 
stirred,  it  is  best  first  to  mix  the  bran  with  water  and  sugar 
and  then  add  the  poison.  The  proportions  are  2  or  3  ounces 
of  sugar  or  a  similar  quantity  of  glucose  or  molasses  to  a  gallon 
of  water  and  sufficient  bran  (about  a  pound  per  gallon)  to  make, 
when  stirred,  a  mixture  that  will  readily  run  through  the  fin- 
gers. Before  planting  a  crop  it  is  advisable  to  use  bait,  and 
for  perfect  success  the  ground  should  be  bare,  which  will  have 
the  effect  of  practically  compelling  the  cutworms  to  feed  on  it. 

Protection  of  plants  that  are  set  out,  such  as  tomato  and  cab- 
bage, started  under  glass,  may  be  secured  by  placing  about  the 
base  of  each  a  tablespoonful  of  poisoned  bran  or  a  small  bunch 
of  the  poisoned  vegetable.  Sometimes  it  is  feasible  to  dip  plants 
like  tomato  and  sweet  potato  in  poison  before  setting  out. 
Arsenate  of  lead  is  best  for  this  purpose  prepared  as  for  spray- 
ing I  pound  to  25 — 50  gallons  of  water.  Where  it  is  possible, 
however,  to  spray  grass  or  weeds  which  have  grown  up  in  fields 
about  to  be  cultivated,  this  should  be  done,  as  it  is  an  easy 
means  for  riddance  of  cutworms  and  less  troublesome  than  the 
preparation  and  distribution  of  baits.  Plants  may  also  be  pro- 
tected by  paper  wrappings  and  tin  collars. 

Bordeaux  mixture  has  been  tested  against  the  variegated  cut- 
worm upon  potato  vines  and  asparagus.  It  was  sprayed  on  as 
a  remedy  for  blight,  and  it  was  discovered  that  plants  thus 
treated  were  free  from  attack.    The  use  of  this  fungicide  as  a 


56  INSECTS    INJURIOUS   TO   VEGETABLES 

cutworm  deterrent  is  certainly  advisable.  In  any  case,  it  should 
be  employed  as  a  diluent  for  whatever  arsenical  is  used. 

Hand  methods. — On  some  plants  it  is  next  to  impossible  to 
apply  any  but  hand  methods  with  good  results.  Experiments 
in  Washington  State  during  1900  demonstrated  conclusively 
that  in  some  cases  it  required  less  time  to  shake  or  brush  the 
variegated  cutworm  from  affected  plants  than  to  destroy  them 
by  spraying  or  otherwise. 

In  ordinary  cases  of  cutworms  in  greenhouses  they  can  be 
held  in  check  by  hand-picking.  It  is  the  custom  of  some  florists 
to  hunt  for  them  at  night  with  a  lantern,  when  they  are  feeding 
and  can  readily  be  discovered  and  destroyed. 

Treatment  as  an  army  worm. — When  cutworms  assume  the 
habit  of  traveling  in  armies  they  should  be  treated  in  the  same 
manner  as  advised  against  the  fall  army  worm  in  pages  which 
will  follow. 

The  Fall  Army  Worm  (Laphygma  frugiperda  S.  &  A.). — The 
fall  army  worm  or  grass-worm  feeds  normally  on  grasses  and 
grains  and  weeds  belonging  to  the  grass  family,  but  will  attack 
in  its  seasons  of  abundance  almost  any  form  of  vegetation  that 
is  encountered  in  its  line  of  march.  At  such  times  it  becomes 
a  pest  in  garden  and  orchard,  on  lawns  and  in  greenhouses,  as 
well  as  in  pastures  and  in  fields  of  grain.  The  moth  is  quite 
unlike  that  of  the  common  army  worm  and  very  variable,  there 
usually  being  two  distinct  forms,  a  dull  gray  and  an  ornamented 
form  (fig.  30,  a  and  h) .  The  hind-wings  are  glistening  white 
with  rosy  reflections.  The  wing  expanse  is  from  an  inch  to  an 
inch  and  three-eighths.  The  eggs  are  deposited  in  clusters  of 
from  fifty  or  more,  often  in  two  or  three  layers.  The  mass  is 
covered  with  down  from  the  body  of  the  moth.  The  differences 
between  this  and  the  true  army  worm  are  shown  by  figures  30,  a, 
^ox  and  31. 

This  insect  is  undoubtedly  native  to  North  as  well  as  South 
America.  Its  greater  abundance  in  semitropical  regions  in- 
dicates that  it  was  originally,  although  not  in  very  recent  times, 


GENERAL    CROP    PESTS 


57 


tropical.  At  present  it  is  more  at  home  in  the  South  where 
opportunity  is  afforded  for  its  increase  in  swamp  land,  among 
wild  rice  and  rank  grasses,  but  it  is  also  acclimatized  in  the 
southern  portions  of  the  North  and  appears  to  be  gradually 
working  its  way  still  farther  northward. 

Injury  has  been  noted  as  far  north  as  Chicago  and  westward 
to  Colorado  and  Montana. 

A  feature  of  this  insect's  attack,  from  which  it  derives  its 
name  of  fall  army  worm,  is  that  it  seldom  does  appreciable  in- 


Fig.  30— Fall  army  worm,  a.  Moth,  plain  gray 
form:  b,  fore-wing  of  Prodenia-like  form;  c,  larva; 
d,  abdominal  segment  of  larva;  e.  pupa.  d.  Twice 
natural  size;  others  enlarged  one-fourth.  (Authors 
illustration,  U.  S-  Dept.  Agr.) 


^^ 


Fig.    30x.-a, 
-  Head    ot    fall 

army  worm;  b. 

of  army  worm. 

Both  enlarged. 


jury  except  in  the  fall.  It  is  not  often  noticed,  therefore,  except 
in  the  extreme  South,  earlier  than  the  first  of  August,  while 
the  outbreaks  of  the  common  army  worm  usually  occur  prior 
to  that  time. 

There  is  no  doubt  that  there  are  two  or  three  generations 
produced  each  year,  and  each  succeeding  generation  usually 
becomes  more  destructive.     It  attacks  practically  all  vegetables. 

The  larvae,  in  years  of  ordinary  abundance,  live  like  cutworms 


58  INSECTS    INJURIOUS   TO   VEGETABLES 

and  are  so  dark  and  evidently  secretive  in  their  nature  as  to 
usually  escape  recognition.  When,  however,  an  undue  increase 
in  numbers  takes  place  and  the  habit  of  moving  in  armies  is 
assumed,  their  presence  becomes  manifest,  too  late,  however, 
in  most  instances,  for  remedial  treatment.  Transformation  to 
pupa  takes  place  in  little  earthen  cells,  but  occasionally  pupae 
are  not  so  protected. 

Methods  of  Control. — In  the  case  of  large  armies  in  ex- 
tensive fields,  poisons  are  of  little  value  when  outbreaks  are  at 
their  height.  When  the  armies  are  first  noticed  the  "worms" 
are  as  a  rule  approaching  maturity,  they  have  effected  much 
damage,  and  it  is  difficult  at  this  stage  to  prevent  them  from 
passing  from  one  field  or  other  tract  to  another.  It  follows 
that,  although  arsenical  poisons  are  valuable  in  many  cases,  we 
must  place  more  reliance  in  preventives  such  as  cultural  and 
mechanical  methods. 

In  fields  of  young  grain  and  on  lawns  many  "worms"  may 
be  killed  by  crushing  with  a  heavy  roller,  when  the  insects  are 
at  work  early  in  the  morning  or  toward  dusk.  In  fields  that 
are  injured  beyond  recovery,  sheep  or  other  cattle  may  be 
turned  in  in  numbers  with  benefit,  as  they  will  kill  the  larvae 
by  trampling  upon  them. 

Other  useful  methods  of  this  nature  include  trenching  or 
ditching,  or  plowing  deep  furrows  in  advance  of  the  traveling 
hosts  to  entrap  the  larvae  which  will  fall  into  them,  and  here 
they  may  be  crushed  by  dragging  logs  or  pieces  of  brush  through 
the  furrows.  If  possible  to  fill  the  trenches  with  water,  or  if 
they  become  partially  filled  by  rains,  the  addition  of  a  small 
quantity  of  kerosene,  so  as  to  form  a  thin  scum  over  the  surface 
of  the  water,  will  prove  fatal  to  the  "worms." 

Rotation  of  crops  should  always  be  practiced,  as  well  as 
burning  over  fields  when  they  are  too  badly  infested  to  recover. 
Above  all  other  precautions  necessary  to  secure  immunity  from 
attack  is  that  of  keeping  the  fields   free  from  volunteer  grain 


GENERAL    CROP    PESTS 


59 


and  wild  grasses,  since  experience  shows  that  these  are  the 
favorite  breeding  grounds  of  the  insect ;  when  the  larvae  hatch- 
ing from  these  eggs  have  devoured  the  grain  and  grasses  they 
are  driven  to  cultivated  fields  for  food. 

Fall  plowing  and  disking  should  always  be  practiced  where 
circumstances  will  permit. 

The  Army  Worm  (Hcliophila  [Lcucaiiia]  nnipimcta  Haw.). — 
The  true  army  worm  is  so  well  known  as  a  grain  and  grass 
pest  that  a  short  account  only  need  be  given,  more  particularly 
since  it  seldom  injures  vegetables  other  than  corn.  Its  general 
economy  closely  resembles  that  of  the  fall  army 
worm,  previously  treated.  The  army  worm  proper 
(fig.  31)  is  larger,  a  little  stouter,  more  distinctly 
striped  and  much  smoother  than  the  fall  army 
worm,  measuring  about  an  inch  and  a  fourth  in 
length.  The  parent  army  worm  is  a  pale  yellow- 
ish brown  moth  with  a  white  spot  near  the  center 
of  each  fore-wing.  This  insect  appears  much 
earlier  in  the  year  than  the  fall  species.  From 
May  to  July  it  accomplishes  its  greatest  injury; 
and  although  nocturnal  by  nature,  when  conditions 
favor  its  increase  it  soon  exhausts  its  food  supply, 
crowds  then  gather  and  march  in  armies — the 
habit  from  which  it  has  received  its  name — in  the 
heat  of  the  day  as  well  as  at  night 


-,..  .      Fig.  31.— Army 

Wmter   is     ^^^^_    ^bout 


passed   usually   in  the   partially   grown   caterpillar     one-third  en- 

...  ,  T     •  -larged. 

State  m  the  same  manner  as  with  cutworms,   injury 

may  be  accomplished  by  any  generation,  but  is  most  often  due  to 

the  second  brood. 

Remedies  are  practically  the  same  as   advised   for  the   fall 
army  worm. 


6o 


INSECTS    INJURIOUS   TO   VEGETABLES 


MISCELLANEOUS    CATERPILLARS 

Caterpillars  of  omnivorous  habits  other  than  cutworms  and 
webworms  may  be  divided  into  two  groups — naked  and  hairy 
caterpillars.  •  Both  forms  are  in  the  main  diurnal,  at  least  during 
their  early  stages,  but  some  naked  species  as  they  approach 
maturity  crawl  into  shelter  where  they  are  more  or  less  pro- 
tected from  the  sun's  ravs  as  well  as  from  natural  enemies.    The 


Fig.  32.— Yellow  bear,  a,  Female  moth;  b,  full-grown  larva;  c,  light  form  of  larva,  not 
quite  mature;  d,  cocoon;  e,  pupa-  All  slightly  enlarged.  (Author's  illustration, 
U.  S.  Dept.  Agr.) 

naked  caterpillars  are  more  abundant  and  injurious,  and  include 
such  species  as  the  zebra  and  clover  caterpillars  and  corn-ear 
worm.  Among  the  hairy  caterpillars  are  such  well-known  forms 
as  the  yellow  bear  (Diacrisia  virginica,  figure  32),  salt-marsh 
and  hedgehog  caterpillars  and  smeared  dagger.  Most  hairy 
caterpillars  are  rather  more  abundant  on  useless  plants  than  on 
crops,  a  fortunate  thing  for  the  grower. 


GENERAL    CROP    PESTS 


6i 


Garden  Webworm  (Loxostcgc  similalis  Gn.). — This  species 
affords  an  excellent  example  of  an  insect  that  feeds  normally 
on  weeds  and  only  in  times  of  abundance  becomes  a  pest  and 
general  feeder.  In  such  times  it  will  attack  most  vegetables. 
In  1885  a  serious  outbreak  occurred  over  a  large  area  in  Kansas, 
Nebraska,  Missouri,  Arkansas,  Texas,  and  in  what  was  then 
known  as  Indian  Territory.   Corn  suffered  most  and  a  replanting 


Fig.  33. — Garden  webworm.  a,  Male  moth;  b,  larva,  lateral  view;  c,  larva,  dorsal  view; 
d,  anal  segment;  e,  abdominal  segment,  lateral  view;  /,  pupa;  g,  cremaster.  (After 
Riley,  except  c,  Chittenden,  U.  S.  Dept.  Agr.) 

was  necessary  in  several  instances,  and  the  yield  per  acre  was 
much  reduced,  owing  largely  to  the  ravages  of  this  webworm. 

The  moth  (fig.  33,  a)  is  variable,  yellow,  buff,  or  reddish- 
brown.  It  has  an  expanse  of  wing  of  about  three-quarters  of 
an  inch.  The  larva  (b,  c)  varies  also,  the  ground  colors  run- 
ning through  pale  and  greenish  yellow  to  dark  yellow.  It  is 
strongly  marked  with  black,  piliferous  spots   ((/,  c). 

The  garden  webworm  occurs  generally  throughout  the  United 
States  and  is  most  injurious  in  the  South.  Its  favored  natural 
food  plant  is  "careless"'  weed  ( Amaranthus).  The  caterpillar, 
soon  after  hatching,  draws  together  the  edges  of  a  leaf  by 
means  of  its  web,  or  fastens  together  two  contiguous  leaves, 
forming  a  shelter,  from  which  it  crawls  forth  to  feed. 

Remedies. — A  spray  of  Paris  green  has  been  used  with  per- 
fect satisfaction  against  this  webworm,  the  fact  that  it  is  more 


62  INSECTS    INJURIOUS    TO   VEGETABLES 

or  less  surrounded  by  webs  and  leaftissues  offering  little  or  no 
barrier  to  the  effects  of  the  poison.  In  addition,  clean  cultural 
methods,  including  late  plowing  in  the  fall  followed  by  deep 
plowing  in  spring,  and  the  burning  of  all  waste  material  and 
weeds,  are  of  service  in  controlling  this  pest.  Early  planting  is 
useful  as  a  safeguard  for  some  crops. 

LEAF-BEETLES 

Leaf-beetles  (Chrysonielidcc)  are  among  the  most  important 
groups  of  insects,  economically  speaking.  Many  of  them  select 
in  the  larval  stage  single  species  or  plants  of  the  same  or 
similar  botanical  families,  but  the  beetles  are  more  inclined  to 
be  omnivorous,  and  some  devour  nearly  all  forms  of  vegetation. 
Their  larval  habits  are  variable,  but  a  considerable  proportion 
subsist  on  plant  tissue  on  the  external  surface  of  leaves.  A 
smaller  number  develop  in  mines  which  they  construct  in  the 
leaves  or  in  the  roots,  in  fruits  and  seeds,  and  even  in  flower 
heads  and  in  stems.  A  familiar  example  of  a  leaf-beetle  larva 
that  lives  externally  on  leaves  is  the  Colorado  potato  beetle,  and 
of  the  root-feeders  are  the  corn  root-worms.  An  example  of 
those  which  live  in  seeds  is  the  twelve-spotted  asparagus  beetle. 
Such  as  feed  on  the  outer  surfaces  of  leaves  are  more  or  less 
grub-like,  with  six  true  legs  and  a  proleg  at  the  posterior  ex- 
tremity. Their  colors  are  often  well  marked,  red  or  yellow, 
with  rows  of  black  spots  as  in  the  case  of  the  Colorado  potato 
beetle.  The  root-feeders,  however,  are  pale,  frequently  white 
and  elongate,  even  threadlike  in  form. 

The  greatest  amount  of  injury  is  generally  due  to  the  hiber- 
nated beetles  on  young  and  tender  plants  before  they  have  made 
good  growth.  Some  species,  indeed,  cause  little  trouble  after 
this  period,  while  others,  like  the  Colorado  beetle,  occasion 
losses  of  greater  or  less  extent  throughout  the  growing  season 
of  the  plants  which  they  affect. 

Our    most    common    omnivorous    leaf-beetle    is    the    twelve- 


GENERAL    CROP    PESTS  63 

spotted  cucumber  beetle  (fig.  3),  the  parent  of  the  southern 
corn  root-worm.  It  will  be  considered  more  at  length  in  the 
chapter  on  corn  insects. 

FLEA-BEETLES 

Flea-beetles  (Halticini)  constitute  a  sub-family  of  the  leaf- 
beetles.  They  are  of  elongate  oval  form  and  similar  color, 
frequently  striped  like  the  cucumber  beetle,  and  may  be  dis- 
tinguished by  their  enormously  developed  hind  thighs,  which 
furnish  them  with  powerful  leaping  ability.  The  most  injurious 
forms  are  minute  and  dark-colored.  Their  habit  of  suddenly 
hopping  from  the  vegetable  on  which  they  are  feeding  has  given 
them  the  common  name  of  flea-beetles  or  fleas,  some  species 
being  known  as  "potato  flea,"  "cabbage  flea,"  etc.,  according  to 
the  plant  infested.  Many  flea-beetles  are  general  feeders,  and 
nearly  all  are  subject  to  a  periodicity,  dependent  on  factors  with 
which  we  are  little  acquainted,  but  doubtless  in  large  part 
traceable  to  atmospheric  conditions,  moist  weather  furnishing 
the  best  conditions  for  the  development  of  the  young  or  larvae, 
and  dry  weather  being  inimical  to  their  increase,  this  hypothesis 
being  based  upon  the  knowledge  that  the  larvae  of  many  species 
are  subterranean. 

Injury  is  frequently  very  severe  on  young  plants  and  is  due 
in  the  greatest  measure  to  the  ravages  of  the  adult  flea-beetles 
which  frequently  appear  in  prodigious  numbers  in  cultivated 
fields  and  like  a  pestilence  sweep  everything  before  them,  their 
depredations  often  necessitating  the  replanting  of  entire  crops. 

The  larvae  of  most  flea-beetles  develop  in  weeds,  a  compara- 
tively small  proportion  living  on  cultivated  crops.  Knowledge 
of  this  fact  is  of  value  in  indicating  methods  of  control. 

The  Pale-striped  Flea-beetle  (Systcna  blanda  Mels.)  is  a  de- 
structive vegetable-feeding  species.  It  measures  about  an 
eighth  of  an  inch,  is  cream-colored,  with  nearly  black  abdomen 
and  eyes,  and  the  wing-covers  are  ornamented  with  a  bright 
sutural  and  two  narrower  marginal  stripes  of  dull  light  brown 
(fig.  34,  h).  The  larva  is  white  and  slender,  with  light  brownish- 


64 


INSECTS    INJURIOUS   TO   VEGETABLES 


yellow  head.  The  legs  end  in  blunt  padlike  processes.  It  is  an 
American  species  and  of  rather  wide  distribution,  from  New 
Jersey  southward  to  Georgia  and  westward  to  California.  The 
beetle  is  nearly  omnivorous  and  injurious  to  beans,  beets,  po- 
tatoes, tomatoes,  eggplant,  corn,  carrot,  melon  and  other  cucur- 
bits, turnip  and  other  crucifers.  It  also  attacks  strawberry, 
cotton,  oats,  peanuts  and  the  leaves  of  pear.  The  beetles  some- 
times do-  severe  damage  in  three  or  four  days.  The  species 
hibernates  as  a  beetle,  and  appears  in  the  vicinity  of  the  District 


Fig  34  —Pale-striped  flea-beetle,  a.  Larva;  b,  beetle;  c,  eggs;  d,  sculpture  of  egg; 
e,  anal  segment,  from  side;  /,  same  from  above,  a-d,  six  times  natural  size;  e,  f,  much 
enlarged.    (Author's  illustration,  U.  S-  Dept.  Agr.) 


of  Columbia  early  in  June;  egg  laying  continues  to  the  middle 
of  July,  if  not  later;  injury  is  usually  due  to  the  beetles  upon 
their  first  appearance  and  almost  any  valuable  crop  may  be 
injured.  The  larvae  live  below  the  ground,  and  have  been  ob- 
served by  the  writer  and  others  feeding  on  roots  of  corn,  lamb's- 
quarters  and  Jamestown  weed. 

The  Banded  Flea-beetle  (Systcna  tccniata  Say). — The  banded 
flea-beetle  has  similar  habits  to  the  preceding  and  similar  struc- 
ture ;  it  was  in  fact,  until  quite  recently  very  generally  confused 
with  the  pale-striped  form,  and  many  references  to  injuries  by 
it  are  really  due  to  the  latter.     Like  the  latter  it  varies  con- 


GENERAL    CROP  PESTS  65 

siderably.     It  is  polished  black  with  white  stripes.     A  common 
dark  form  is  shown  in  figure  35. 

METHODS    OF    CONTROL 

Arsenicals  and  Bordeaux  mixture. — The  best  remedies  for 
leaf-beetles  and  flea-beetles  are  Paris  green  or  other  arsenical 
and  Bordeaux  mixture,  either  in  combination  or  separately. 
Bordeaux  mixture  alone  acts  as  a  deterrent,  and  the  writer  sug- 
gests that  instead  of  using  either  one  separately,  or  both  in 
combination,  that  the  greater  portion  of  an  infested  field  or 
garden  be  sprayed  with  the  Bordeaux  mix- 
ture freely  and  as  often  as  may  be  nec- 
essary, particularly  after  heavy  rains, 
while  strips  here  and  there  be  sprayed  ex- 
clusively with  Paris  green.  This  will 
have  the  effect  of  driving  the  beetles  from 
the  Bordeaux-sprayed  plants  to  the  poi- 
soned ones.  Paris  green  alone,  dusted  dry 
on  infested  plants,  is  thoroughly  effective 
against  many  species.     Arsenate   of   lead 

.        ,,  .  .  ,  Fig.  35.— Banded  flea-beetle, 

is  preferable  for  spraymg  tender  dark  variety.  (Author's  ii- 
plants  like  beans,  whose  foliage  is  lustration,  u.S.Dept.Agr.) 
liable  to  scorching.  Plants  like  to- 
mato, eggplant,  and  cabbage  that  are  started  under  glass  and 
that  are  liable  to  flea-beetle  attack,  should  be  dipped  in  a 
solution  of  Bordeaux  mixture  and  Paris  green  or  lead  arsenate 
before  transplanting.     For  direction  see  page  55. 

Kerosene  emulsion  and  soap  washes,  even  strong  soap-suds, 
have  been  used  with  profit  in  combating  some  flea-beetles. 

Pyrethrum,  dry,  mixed  with  flour  or  road  dust,  may  be  em- 
ployed for  small  gardens. 

Cultural  methods. — In  the  protection  of  young  plants  knowl- 
edge of  the  fact  that  the  larvae  of  many  species  subsist  by 
preference  on  weeds  must  be  remembered,  and  the  grower 
should,  moreover,  familiarize  himself  with  the  particular  natural 


66  INSECTS    INJUKIOLIS    TO    VECETAHLES 

or  wild  food  of  the  beetles  which  injure  his  crops.  Thus  night- 
shade and  Jamestown  weed  harbor  the  larvae  of  the  Colorado 
beetle  and  flea-beetles  which  attack  potato  and  eggplant,  and  it 
is  therefore  imprudent  to  plant  crops  in  fields  which  have 
produced  such  weeds.  Injury  to  corn  by  corn  root-worms  is  in 
many  cases  directly  traceable  to  planting  in  corn  land,  and  fllea- 
beetle  damage  to  corn  follows  when  this  crop  is  grown  in  soil 
previously  in  grasses  which  furnish  food  for  their  larvae.  In 
the  same  manner  leaf-beetles  and  flea-beetles  which  attack  beans 
and  beets,  breed  in  such  common  weeds  as  lamb's-quarters. 

At  the  same  time  that  beetles  are  ravaging  our  crops,  they 
may  also  occur  on  nearby  weeds,  and  for  thorough  work  the 
insects  should  be  destroyed  by  poisons  or  other  means  on  the 
wild  as  well  as  the  cultivated  plants. 

Poultry  and  toads  are  fond  of  leaf  and  flea-beetles,  and  it 
is  recommended  to  encourage  these  valuable  aids  to  the  farmer, 
by  placing  coops  of  chickens  or  other  young  fowl  in  vegetable 
gardens  and  to  protect  the  toads. 

BLISTER    BEETLES 

Many  species  of  blister  beetles  {Mdoidcc)  are  very  destructive 
to  vegetables,  particularly  in  the  Southwest,  and  especially  to 
potatoes  and  beets,  beans,  peas,  and  other  leguminous  crops. 
They  are  gregarious  and  in  their  season  habitually  congregate 
in  great  numbers.  Some  have  the  migratory  habit,  feeding 
voraciously,  running  with  great  rapidity,  and  flying  from  time 
to  time.  Thus  it  happens  that  they  frequently  descend  in  such 
numbers  on  a  field  that  a  crop  is  ruined  in  a  few  days,  when 
the  insects  go  elsewhere  or  disappear  and  are  perhaps  seen  no 
more  until  the  following  year.  After  the  departure  of  one 
species  of  blister  beetle  another  frequently  follows,  to  be  -re- 
placed sometimes  by  a  third.  Blister  beetles  are  not  an  unmixed 
evil,  however,  since  they  do  some  good  in  their  larval  stage  to 
compensate    for   the   harm    the   beetles   occasion   to   our   crops. 


GENERAL    CROP    PESTS 


67 


Their  larvae  destroy  grasshopper  eggs  and  thus  aid  in  keeping 
these  pernicious  insects  in  check.  This  is  especially  true  where 
both  blister  beetles  and  grasshoppers  abound.  But  the  benefits 
derived  are  really  more  than  counterbalanced  by  the  losses  oc- 
casioned by  the  rapacity  of  the  beetles ;  hence  measures  should 
be  employed  to  destroy  them  when  they  occur  in  harmful  num- 
bers. Blister  beetles  are  apt  to  be  found  in  practically  all  veg- 
etable fields. 

The  Striped  Blister  Beetle  (Epicauta  vittata  Fab.). — Before 
the  advent  of  the  Colorado  beetle  this  was  considered  the  most 


Fig.  36.  — Striped  blister 
beetle  {Epicauta  vittata). 
Female  beetle.  (Author's  il- 
lustration, U.  S.  Dept.  Agr.) 


Fig.  37.— Three-lined  blis- 
ter beetle  (Epicauta  lemni- 
scata).  (Author's  illustration, 
U.  S.  Dept.  Agr.) 


destructive  potato  pest  of  the  East  and,  probably  because  it  is 
striped  somewhat  like  the  latter,  it  is  more  often  called  "old- 
fashioned  potato  bug"  than  other  species.  It  can  be  easily 
identified  by  means  of  the  illustration  (fig.  36).  Although  much 
attached  to  the  potato,  this  species  also  does  injury  to  beets, 
beans,  peas,  tomatoes,  radishes,  and  melons. 

The  Three-lined  Blister  Beetle  (Epicauta  lemniscafa  Fab.). — 
This  blister  beetle  very  closely  resembles  the  preceding;  in  fact, 


68 


INSECTS    INJURIOUS    TO    VEGETABLES 


the  two  are  frequently  confounded,  and  injuries  inflicted  by  one 
attributed  to  the  other.  The  form  under  consideration  (fig.  2)7) 
is  a  little  more  slender,  has  three  stripes  on  each  wing-cover 
instead  of  two,  and  is  a  little  longer.  It  is  very  abundant  south- 
ward, and  is  partial  to  potato,  cabbage,  squash,  and  to  beet  tops. 
The  Spotted  Blister  Beetle  (Epicanta  maculafa  Say). — The 
southwestern  portion  of  the  United  States  is  the  home  of  many 
species  of  blister  beetles  not  found  in 
the  north  and  east.  Among  the  most 
abundant  is  the  species  illustrated  in 
figure  38.  Its  body  is  covered  with 
fine  gray  hairs,  with  small  areas  on 
the  elytra,  through  which  the  natural 
black  of  the  body  shows,  giving  it  the 
appearance  of  a  gray  insect  finely 
dotted  with  black.  It  abounds  from 
Texas  and  New  Mexico  northward  to 
South  Dakota,  thence  westward  to 
California  and  Oregon.  It  is  found 
upon  potato,  beet,  clover  and  other 
plants. 
Remedies. — Paris  green  is  one  of  the  best  remedies  for  blister 
beetles  when  they  occur  on  potatoes  and  most  other  crops.  It 
may  be  applied  dry,  or  as  a  spray,  according  to  directions  al- 
ready given  in  the  discussion  of  insecticides.  Arsenate 
of  lead  is  also  excellent  for  these  pests.  Repeated  ap- 
plications are  sometimes  necessary,  since  the  poisoned  beetles 
are  replaced  by  others.  A  remedy  employed  with  success  in 
the  West  consists  in  sending  a  line  of  men  and  boys  through 
infested  fields  to  drive  the  beetles,  by  short  flights  and  running, 
before  them  until  they  alight  in  windrows  of  hay,  straw,  or 
other  dry  vegetable  material  which  have  previously  been  pre- 
pared along  the  leeward  side  of  the  field.  When  the  beetles 
have  taken  refuge  in  such  a  windrow,  it  is  fired  and  the  beetles 


Fig.     38.— Spotted    b 
beetle.      (Author's    illustra' 
tion,  U.  S.  Dept.  Agr.) 


GENERAL    CRUl'    TESTS  69 

are  burned.     Whatever  remedy  is  employed  should  be  applied 
at  the  outset  of  attack  in  order  to  be  of  substantial  value. 


GRASSHOPPERS   AND    RELATED    INSECTS 

Of  great  importance  in  the  West,  and  in  some  seasons  in  other 
regions,  are  numerous  species  of  locusts,  or  short-horned  grass- 
hoppers. Several  related  insects,  such  as  katydids  and  crickets, 
are  also  injurious.  All  of  these  are  general  feeders,  and  as  a 
rule  destructive  to  vegetable  crops  only  in  seasons  which  have 
been  particularly  favorable  to  their  multiplication.  The  num- 
bers of  species  of  these  insects  mount  into  the  hundreds,  but 
the  most  important  forms  might  be  reduced  to  a  double  score. 

For  present  purposes  it  will  be  necessary  to  mention  only  a 
few  of  the  most  abundant  forms.  Grasshoppers  are  mostly 
large  insects,  with  mouth-parts  formed  for  biting,  with  young 
more  or  less  closely  resembling  the  adults,  save  for  the  lack  of 
wings.  Their  name  is  sufficient  indication  of  their  habits:  they 
live  normally  in  grasses,  and  their  hind  thighs  are  enlarged 
for  leaping.  Everyone  knows  them  so  well  that  further  descrip- 
tion is  unnecessary.  Some  species  are  capable  of  extended 
flight  for  hundreds  of  miles  with  intermissions  of  daily  stops 
for  food.  At  such  times  they  occur  in  swarms,  and  sometimes 
darken  the  face  of  the  sun,  or  at  night  of  the  moon. 

Grasshoppers  may  be  classified  in  regard  to  their  habits  as 
non-migratory  and  migratory.  In  the  latter  group  are  our  com- 
monest species  which  breed  and  pass  their  entire  lives  in  or 
near  the  place  where  the  eggs  were  laid  from  which  they  de- 
velop. The  migratory  species  develop  in  enormous  numbers, 
and  when  they  become  too  abundant  for  the  food  supply  of  the 
region  where  they  originated  they  migrate.  They  are  most 
troublesome  in  arid  and  semi-desert  regions,  and  their  numbers 
are  subject  to  variation  according  to  climatic  conditions  and 
locality.     Dry  regions  are  liable  to  the  visitatioii  of  a  locust 


70 


INSECTS    INIURIOL'S     lO   VKCETARLES 


swarm  at  any  time  of  the  year,  and  they  are  the  most  dreaded 
of  pests,  because  of  the  rapidity  of  their  attack,  when  they  lay 
waste  large  districts,  and  even  considerable  portions  of  states. 
The  Red-legged  Locust  (Mclanoplus  femur-rubrum  DeG.). — 
This  is  our  commonest  North  American  grasshopper,  being 
found  practically  everywhere.  It  is  one  of  the  smaller  species 
(fig.  39),  and  where  it  is  not  held  in  subjection  by  natural 
enemies  it  may  become  a  de- 
cided nuisance  in  cultivated 
lands.  It  seldom  exhibits  the 
migratory  tendency,  but  some- 
times gathers  in  swarms  and 
moves  in  concert,  not,  however, 
rising  to  great  heights,  but  drifting  with  the  wind  as  do  the  true 
migratory  species. 

The  Rocky  Mountain  Locust  {Mclanoplus  sprctns  Thomas). 
— This  is  the  most  destructive  of  all  native  grasshoppers,  and 
has  been  the  cause  of  greater  losses  to  agriculture  in  the  past 
than  perhaps  all  of  the  other  known   species  of  grasshoppers 


Fig   39- — Melanoplus  femur-rubrum 
Natural  size.    (After  Riley) 


Fig.  40.— Reeky  Mountain  locust,  a.  a.  a.  Female  ovipositing;  b,  egg-pod  extracted 
from  ground,  with  end  broken  open;  c.  a  few  eggs  lying  loose  on  ground;  d.  e, 
earth  removed,  to  illustrate  egg-mass  in  place  and  one  being  placed;/,  where  a  mass 
has  been  covered  up.    (After  Riley). 


GENERAL    CROP    PESTS  7I 

combined.  Its  range  of  injuriousness  is  not  limited  to  the  Rocky 
Mountain  region,  but  it  is  more  abundant  there  than  elsewhere. 
It  is  illustrated  in  figure  40.  Those  who  were  interested  in 
farming  in  the  7o"s  in  Kansas,  Nebraska,  and  some  neighboring 
states  have  cause  to  remember  the  depredations  of  the  Rocky 
Mountain  locust.  During  1874-1877  it  was  directly  responsible 
for  the  loss  of  $100,000,000,  in  addition  to  an  indirect  loss  by 
the  stoppage  of  business  and  other  enterprises  which  might 
have  aggregated  as  much  more.  It  was  for  an  investigation  of 
this  species  that  the  United  States  Entomological  Commission 
was  formed,  which  published  from  1877  to  1879  two  voluminous 
reports  on  it  alone. 

The  Differential  Locust  {Mclanoplus  diffcrentialis  ThomdLs). — 
In  the  Middle  West  the  farmer  is  much  bothered  at  times  by 


i\-—Melanoplus  differenhalis-    Natural  size 
(After  Riley) 

the  large  yellow  locust,  shown  in  figure  41.  It  is  found  along 
roadsides  and  on  the  edges  of  groves,  preferring  rank  vegeta- 
tion where  such  abounds.  When  it  becomes  unusually  numer- 
ous it  is  quite  destructive  to  vegetable  crops  and  to  cereals. 

METHODS    OF    CONTROL 

Locusts  or  grasshoppers  are  largely  kept  within  normal  num- 
bers by  numerous  enemies,  among  which  are  many  large  forms 
of  insectivorous  birds  and  mammals,  batrachians  and  reptiles. 
They  also  have  large  numbers  of  predaceous  and  parasitic  insect 
enemies,  which  kill  them  off  in  ordinary  seasons.  With  changes 
of  the  weather,  however,  the  insect  enemies  are  frequently  de- 
stroved,  and  then  the  locusts  become  abundant.     In  such  cases 


72  INSECTS    INJURIOUS   TO   VEGETABLES 

the  grasshoppers  can  be  controlled  by  several  artificial  methods. 
The  remedies  that  have  proved  most  efficient  are  plowing  under 
the  eggs  before  these  have  had  time  to  hatch,  and  the  capture 
by  means  of  hopper-dozers  of  the  unfledged  locusts,  as  well 
as  many  of  those  which  have  become  winged.  These  are  shallow 
sheet-iron  pans  in  which  are  placed  tar  or  coal-oil  tar  or  kero- 
sene oil,  and  which  may  be  drawn  or  pushed  by  hand  over  the 
ground  or  by  horses,  in  such  a  manner  that  the  hoppers  will 
leap  into  the  pans  and  be  killed  by  coming  into  contact  with 
the  tar  or  oil.    Hopper-dozers  are  shown  in  figures  2iy  and  210. 

Other  remedies  of  great  value  in  the  prevention  of  injury  to 
our  cultivated  crops  are  the  bran-arsenic  mixture  and  poisoned 
horse  droppings.  Directions  for  preparing  the  former  have 
been  given  on  page  54. 

Poisoned  horse  droppings  consist  of  i  part  of  Paris  green 
mixed  thoroughly  in  60  parts  of  fresh  horse  droppings,  2  pounds 
of  salt  to  half  a  barrel  of  mixture  being  added  after  being  dis- 
solved in  water.  This  is  placed  in  half  barrels  and  drawn  on 
carts  to  the  edge  of  the  infested  field  or  one  likely  to  be  invaded. 
The  mixture  is  then  scattered  broadcast  along  the  edge  of  the 
crop,  or  wherever  needed,  by  means  of  a  trowel  or  wooden 
paddle.  The  locusts  are  attracted  to  it  and  are  killed  in  large 
numbers  by  eating  the  poison.  Although  this  mixture  is  "sure 
death,"  it  sometimes  requires  from  two  to  five  days  for  it  to 
kill  the  locusts. 

Turkeys  are  of  great  value  in  freeing  orchards  and  vine- 
yards of  locusts,  and  they  may  be  employed  in  other  fields  for 
the  same  purpose.  In  one  case  a  flock  of  766  turkeys  were  kept 
at  work  in  the  destruction  of  grasshoppers.  The  turkeys  have 
to  be  watched,  as  they  sometimes  vary  their  diet  with  vegetables. 

In  some  cases  it  has  been  possible  to  ascertain  the  particular 
breeding  places  of  grasshoppers,  some  species  depositing  their 
eggs  in  pasture  lands  and  among  foothills  at  the  bases  of 
mountains  in  the  Far  West,  in  regions  in  which  the  tar  weed 


GENERAL   CROP    PESTS  73 

grows.  Here  the  eggs  can  be  destroyed *by  burning  over  the 
ground  late  in  the  fall  after  all  of  the  eggs  are  deposited,  or 
by  plowing  them  in  to  a  depth  of  six  or  eight  inches  before 
they  hatch  in  the  spring. 

In  case  it  is  for  any  reason  not  feasible  to  employ  any  of 
these  last  mentioned  remedies,  and  the  place  of  egg  deposit  is 
ascertained,  a  watch  should  be  kept  for  the  young  grasshoppers, 
and  they  should  be  destroyed  as  soon  as  possible  after  hatching 
by  means  of  bran-arsenic  mash. 

Cooperation  is  greatly  desirable  in  the  treatment  of  grass- 
hoppers, particularly  in  regions  where  they  reach  their  greatest 
development ;  and  the  thoroughness  with  which  work  is  done 
in  one  year  will  show  the  next  season  in  the  greatly  reduced 
numbers  with  which  the  farmers  will  have  to  deal. 

Remedies  for  grasshoppers  in  general  are  applicable- to  the 
migratory  species,  but  the  latter  sometimes  occur  in  such  im- 
mense swarms  that  it  is  difficult  to  treat  them.  It  is  of  the 
highest  importance  that  whatever  remedies  are  employed  must 
be  used  at  the  very  first  onset  and  generally  over  considerable 
territory,  as  the  insects  fly  from  one  field  to  another. 

WHITE    GRUBS 

White  grubs  occupy  a  prominent  position  among  the  many 
insect  foes  to  agriculture.  There  are  several  hundred  distinct 
forms  of  these  creatures,  each  representing  a  different  species 
of  the  family  Scarabaeidae.  A  considerable  number  are  of  prime 
importance  economically,  the  remainder  are  less  injurious  or 
do  not  attack  useful  plants.  The  noxious  forms  subsist  on 
roots  and  are  very  abundant  under  sod,  and  in  similar  locations. 
Of  these  a  considerable  majority  of  the  typical  white  grubs 
belong  to  the  genus  Lachnosterna,  of  which  nearly  a  hundred 
species  are  known. 

The  parents  of  white  grubs  are  known  as  May  beetles  or 
"May  bugs"  in  the  South  and  Middle  states,  and  as  June  beetles 


74  INSECTS    INJURIOUS   TO   VEGETABLES 

or  "June  bugs"  in  the'North,  from  their  occurrence  in  numl)crs 
in  these  months  in  these  dififerent  regions.  Injury  is  by  no 
means  confined  to  the  white  grubs,  but  can  often  be  laid  to  the 
account  of  the  beetles,  but  the  latter  are  most  destructive  to 
shade  and  fruit  trees. 

White  grubs  or  "grub-worms,"  with  wireworms  and  cutworms 
were  the  original  inhabitants  of  the  soil  before  the  advent  of 
civilized  man.  They  lived  in  our  open  prairies  when  America 
was  still  a  wilderness,  and  they  continue  to  dwell  in  our  grass 
lands,  meadows,  fields  and  gardens  and  repel  all  attempts  toward 
their  permanent  removal.  The  farmer  who  imprudently  plants 
corn  or  potatoes  in  fields  that  have  long  laid  waste  and  become 
grown  up  with  weeds  and  grasses,  or  where  strawberries  have 
been  the  previous  season,  does  so  at  the  risk  of  losing  his  crop. 
The  problem  of  how  to  destroy  them  and  to  protect  the  crops 
from  their  ravages  is  a  subject  requiring  constant  and  scientific 
treatment.  Injury  appears  to  be  most  noticeable  to  corn, 
grasses,  small  grains,  beets,  potatoes  and  other  root  crops,  and 
strawberries,  but  the  roots  of  young  shade,  fruit  and  forest  trees 
are  also  attacked. 

As  with  insects  of  similar  habits,  white  grubs  and  May 
beetles  are  liable  to  considerable  fluctuation  of  numbers  in  dif- 
ferent localities  and  years.  This  is  most  noticeable  after  crop 
rotation,  particularly,  as  might  be  inferred  from  what  has  al- 
ready been  said,  where  susceptible  crops  are  planted  in  grass 
lands.  Attack  may  commence  from  the  time  the  plant  sends 
out  roots,  and  continue  for  a  much  longer  time,  as  these  insects 
pass  two  qr  three  years  from  the  egg  until  they  reach  the  adult 
condition.  When  the  larva?  are  present  in  great  numbers  at 
the  roots,  the  plants  soon  die  and  whole  crops  are  ruined. 

In  a  general  way  white  grubs  may  be  described  as  large,  soft 
white  or  yellowish  grubs,  with  wrinkled  bodies,  sparsely  covered 
with  fine  hairs,  having  yellowish  or  brownish  heads  with  strong 
mandibles,  three  pairs  of  distinct  legs  on  the  fore  part  of  the 


GENERAL    CROP    PESTS  75 

l)0(ly  (the  three  thoracic  segments)  and  the  hinder  portion  of 
the  body  considerably  thickened  toward  the  end.  The  normal 
position  of  typical  white  grubs  is  curved,  as  shown  in  figure  42,  e. 
They  crawl  on  their  sides,  not  on  their  backs  as  is  the  case  with 
the  non-injurious  white  grub  of  the  June  beetle. 
The  parents  of  the  injurious  or  typical  white  grubs   (Lach- 


Fig.  42.— Arcuate  May  beetle,     a,  Beetle; 
mature  larva:  /,  anal  segment  of  same. 


I,  pupa;  c,  egg:   d,  newly-hatched  larva; 
(Author's  illustration,  U.  S.  Dept.  Agr.) 


nostcrna  spp.)  are  for  the  most  part  large,  shining  brown  beetles, 
known  to  every  one  from  their  habit  of  flying  into  lighted 
rooms  through  open  windows,  in  late  spring  and  early  summer, 
buzzing  and  bumping  upon  the  ceilings  and  walls  and  finally 
falling  to  the  floor.  A  comparatively  small  number  are  yel- 
lowish, or  plum  color,  and  some  few  are  nearly  black. 

From  April  to  July,  according  to  climate,  these  beetles  appear, 
often  in  great  numbers,  about  our  electric  lights  and  upon  our 
fruit  and  shade  trees,  their  appearance  each  day  beginning  al- 
most uniformly  at  sundown.  They  feed  voraciously  upon  the 
leaves  of  trees,  and  bushes  such  as  blackberry,  but  are  especially 
fond  of  the  foliage  of  nursery  stock  and  other  young  trees, 
particularly  oak,  chestnut,  hickory,  maple,  and  fruit  trees,  often 
doing  such  damage  to  newly  transplanted  shade  and  orchard 
trees  as  to  result  in  their  complete  defoliation  and  destruction. 
The  beetles  fly  and  feed  only  at  night,  and  during  the  day 
remain  perfectly  quiet  in  the  vicinity  of  their  feeding  places. 
It  has  lately  been  shown  conclusively  (what  was  previously  in- 


76  INSECTS    INJURIOUS   TO   VEGETABLES 

f erred  by  deduction)  that  one  species,  Lachnosterna  arcuata,^ 
requires  only  a  little  over  two  years  for  larval  development,  but 
about  three  years  are  consumed  from  the  time  the  egg  is  laid 
until  the  appearance  of  the  beetle  above  the  ground,  and  this 
is  probably  true  of  most  of  the  species  which  occur  in  this 
country.  Thirteen  days  was  ascertained  as  the  egg  period, 
twenty-three  for  the  pupa,  and  the  total  period  from  egg  to 
adult  required  two  years  and  fifty-one  days. 

The  sexes  pair  soon  after  their  first  appearance  and  the 
females  enter  the  earth  for  oviposition.  The  eggs,  which  are 
rather  large  and  whitish  or  gray,  are  deposited  singly  in  the 
ground.  The  grubs,  hatching  among  the  roots  of  grass  and 
similar  plants,  feed  at  first  upon  the  tender  rootlets  and  after- 
ward on  the  larger  roots,  and  slowly  increase  in  size  until  mature. 

The  species  which  have  been  observed  usually  transform  to 
pupae  from  the  middle  of  June  to  September  of  the  second  or 
third  year  after  hatching,  and  become  fully-developed  beetles  in 
August  or  September  of  the  same  year.  They  remain  in  the 
earthen  cells  in  which  transformation  has  taken  place,  some- 
times at  a  depth  of  from  twelve  to  eighteen  inches,  where  they 
are  protected  from  told  and  frost,  and  appear  abroad  the  fol- 
lowing spring  to  repeat  the  life  cycle.  Hibernation  may  occur 
in  two  stages  of  the  larva,  and  occasionally  in  a  third,  and  as 
beetles. 

The  Arcuate  May  Beetle  {Lachnosterna  arcuata  Sm.)  is  the 
common  May  beetle  of  the  Tvliddle  Atlantic  region.  The  North- 
ern June  Beetle  (Lachnostera  fiisca  Frohl.)  is  abundant  in  the 
Middle  Atlantic  region,  and  is  quite  as  destructive  and  over 
a  wider  extent  of  territory.  It  is  the  common  species  from 
New  England  to  Illinois,  and  occurs,  but  comparatively  rarely, 
farther  west.  A  large  proportion  of  the  injury  caused  by  white 
grubs  and  June  beetles  in  the  region  specified  are  due  to  this 
insect. 

1  See  article  by  the  writer,  Bui.  No.  19,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  74-80. 


GENERAL    CROP    PESTS  "JJ 

The  winged  Northern  forms  of  May  beetles  are  replaced  in 
Texas  and  some  other  portions  of  the  South  by  three  common 
species,  two  wingless  {Lachnosterna  cribrosa  Lee.  [fig.  43]  and 
L.  lanccolata  Say)  and  one  with  similar  habits  (L.  farcta 
Lee.)  which  do  great  damage  in  their  beetle  stage  to  trucking 
industries.  They  subsist  largely  upon 
weeds,  hence  in  addition  to  treating  af- 
fected plants  with  arsenicals,  the  weeds 
should  be  similarly  treated.  Late  fall  or 
winter  plowing  and  avoidance  of  weedy 
fields  for  planting  are  advisable  as  pre- 
ventives. Swine  should  be  used  for  de- 
stroying them  and  on  small  areas  hand- 
picking  can  be  employed,  when  the  beetles  p^^  '^^.-Lachnosterna  crib- 
make  their  appearance  an  hour  or  more     ''"■^a-  Female.     (Sander- 

,      .  ,  son,  U.  S.  Dept.  Agr.) 

before  sundown. 

Among  white  grubs  that  are  likely  to  be  mistaken  for  the 
more  injurious  forms  {Lachnosterna  spp.)  are  the  carrot 
beetle,  which  will  be  considered  in  a  later  chapter;  the  "muck 
worm,"  which  occurs  in  manure  and  in  the  droppings  of  cattle, 
and  which  appears  to  be  normally  a  purely  dung-feeding 
species ;  the  sugar-cane  beetle ;  the  rice  grub ;  the  green  June 
beetle,  and  the  brown  fruit-chafer,  which  last  will  be  described 
in  the  consideration  of  insects  affecting  sweet  corn. 

PREDACEOUS    AND    PARASITIC    ENEMIES 

Although  white  grubs  are  apparently  protected  by  their  sub- 
terranean mode  of  existence  and  their  life,  as  beetles,  is  com- 
paratively brief,  many  predatory  animals  as  well  as  parasitic 
and  predaceous  insects  attack  and  destroy  them.  Birds  of  sev- 
eral species  and  most  wild  mammals  which  still  linger  in  cul- 
tivated regions  are  among  this  number.  Domestic  fowls  are 
very  fond  of  white  grubs  and,  when  given  the  opportunity,  fol- 


78  INSECTS    INJURIOUS   TO   VEGETABLES 

low  the  plow  for  them.     Swine  also  search  out  and  eat  many 
which  they  obtain  by  uprooting  the  turf. 
Of  the  insect  enemies  of  white  grubs  are  Tachina  flies,  wasps 


Fig.  AA.—Tiphia  inomata-    Parasite  of  white  grub,    a.  Female  wasp;  b,  head  of 
larva;  c,  larva  from  below;  d.  cocoon  cut  open.    (After  Riley) 

and  parasitic  Hymenoptera,  mites,  and  predaceous  ants.  Among 
these  insects  is  the  wasp,  Tiphia  inomata  (fig.  44).  Under 
certain  conditions  white  grubs  are  also  much  subject  to  infec- 
tion by  fungous  parasites. 

REMEDIES    FOR    WHITE    GRUBS 

Insecticides. — Good  results  have  followed  the  use  of  bisulphid 
of  carbon  and  kerosene  emulsion  against  some  species.  The 
emulsion  is  diluted  about  ten  times  and  poured  on  the  ground 
about  the  infested  plants.  Application  is  made  just  before  rain- 
fall, to  insure  the  emulsion  being  washed  deep  into  the  soil  so 
as  to  come  into  direct  contact  with  the  larvae.  If  rain  does  not 
fall  within  a  day  or  two  a  copious  watering  should  follow  the 
application.     Ga«  lime  is  also  valuable.     (See  page  34.) 

Fall  plowing  is  a  most  effective  remedy.  The  land  should 
be  thoroughly  broken,  and  loosened  to  expose  the  grubs  and 
beetles  to  the  elements  during  winter.  This  is  particularly 
valuable  in  cold  climates,  as  white  grubs  are  unable  to  with- 
stand exposure  to  severe  frost.  Cross-plowing  is  sometimes 
advisable  where  there  is  severe  infestation.  This  will  insure 
the  ground  being  often  disturbed,  and,  if  kept  clean  of  weeds 
and  other  vegetation,  the  grubs  can  be  "wiped  out." 

Preventive  measures  are  still  more   valuable.     The  best  of 


GENERAL    CROP    PESTS  79 

these  consists  in  avoiding  for  the  planting  of  vegetable  crops 
land  which  is  already  known  to  contain  white  grubs  and  espe- 
cially grasslands,  whether  meadow  or  prairie.  Corn  fields  should 
not  be  planted  to  root  crops  and  the  like  without  rotation  with 
clover  or  other  immune  crops.  Summer  fallowing  of  infested 
land  is  said  to  be  useful. 

Rotation  of  crops  is  valuable  in  connection  with  fall  plowing. 
In  case  infested  land  is  desired  for  the  planting  of  corn,  beets, 
potatoes,  or  other  crop  subject  to  severe  injuries  by  white  grubs, 
an  application  of  fertilizer,  such  as  nitrate  of  soda  or  kainit, 
put  on  as  a  heavy  top  dressing  after  the  ground  is  prepared  and 
before  planting,  has  proved  of  benefit  in  some  cases. 

Domestic  animals. — Much  good  may  be  accomplished  by  en- 
couraging domestic  fowls  to  follow  in  the  furrows  to  pick  up 
the  grubs  as  they  are  turned  up  by  the  plow.  Hogs  are  also 
exceedingly  fond  of  white  grubs,  and  if  allowed  the  run  of 
localities  where  these  are  abundant,  after  the  crop  is  made,  they 
will  root  up  the  ground  and  devour  great  numbers  of  them. 

WIREWORMS 

Of  similar  importance  to  white  grubs  as  general  farm  pests 
are  the  wireworms.  Though  not  related  to  the  white  grubs, 
they  have  very  similar  habits,  the  injurious  vegetable-feeding 
forms  being  strictly  subterranean  and  subsisting  at  the  expense 
of  various  crops,  especially  corn,  cereals,  and  grasses,  but  at- 
tacking, in  the  absence  of  these,  various  vegetables  and  other 
plants.  The  subject  of  soil  and  environment  as  regards  attack 
by  wireworms  has  not  been  thoroughly  studied,  but  certain 
species  are  more  numerous  in  sandy  lands,  and  others  are  almost 
always  found  in  unbroken  prairies  and  in  wild  grasses.  Thus 
it  happens  that,  as  in  the  case  of  white  grubs,  injury  is  most 
apt  to  occur  when  corn  and  other  vegetables  are  planted  in  old 
sod,  along  the  borders  of  marshes,   in  pastures  and  meadows. 

Nearly  every  tiller  of  the  soil  is  familiar  with  wireworms, 


8o 


INSECTS    INJURIOUS   TO   VEGETABLES 


and  there  are  many  species,  but,  fortunately,  a  small  percentage 
only,  of  nearly  600  described  forms  have  been  identified  in  con- 
nection with  losses.  From  an  agricultural  viewpoint  they  fall 
into  two  classes,  such  as  feed  upon  living  vegetation,  and  those 
which  subsist  upon  rotten  wood  and  similar  material.  Most  of 
the  noxious  forms  that  have  been  recognized  are  wire-like, 
hence    the    common    name,    and    are    nearly    cylindrical,    hard, 

smooth  and  shining,  and  of 
a  yellowish  or  reddish  color. 
They  have  three  pairs  of 
legs  placed  far  forward  on 
the  anterior  extremity,  and 
the  last  segment  (the  thir- 
teenth counting  the  head) 
ends  in  a  proleg  on  the  un- 


Fig.  45. — Wheat  wireworm.  a.  Beetle:  b, 
larva;  c,  anal  segment  of  larva  in  profile. 
(Author's  illustration,  U.  S.  Dept.  Agr.) 


Fig.  46.  — Common  click- 
beetle.  Three  times  natural 
size.    (After  Forbes.) 


der  surface.  They  are  surprisingly  hard  in  texture  and  among 
the  most  vigorous  insects  known,  being  difficult  to  poison  by 
means  of  anything  that  has  been  tried.  A  common  and  destruc- 
tive species  known  as  the  wheat  wireworm  {Agriotcs  mancus 
Say)  is  illustrated  by  figure  45. 


GENERAL    CROP    PESTS  '  8l 

Wireworms  are  the  offspring  of  snapping  or  click  beetles 
or  "snap-bugs,"  which  are  rather  hard,  pubescent  creatures  of 
elongate,  oval  form,  and  readily  distinguishable  from  any  other 
insects  by  the  habit  from  which  their  common  name  has  been 
derived,  of  vaulting  into  the  air  with  a  sudden  click  when  they 
happen  to  fall  upon  their  backs.  The  common  click-beetle 
(Melanotiis  communis  Gyll.)   is  shown  in  figure  46. 

Of  the  various  vegetable  crops  attacked  potatoes,  according  to 
record,  are  most  injured,  by  having  the  surface  of  the  tubers 
gnawed  into  and  eroded  by  the  worms."  Turnips  suffer  similar 
injury,  as  do  also  to  a  less  extent  carrots,  beets,  cabbage,  onions, 
lettuce,  and  others.  In  attacking  growing  plants  wireworms 
usually  devour  the  smaller  roots  or  tender  tubers,  according  to 
the  plant  affected,  and  in  the  case  of  attack  on  corn  they  fre- 
quently kill  the  plant  by  boring  cylindrical  channels  through 
the  under-ground  portions  of  the  stalk. 

The  life  histories  and  habits  of  wireworms  vary  according 
to  species  and  climate,  but  in  many  respects  they  resemble  the 
white  grubs  so  closely  that  details  may  be  omitted. 

The  Cornell  University  experiment  station  carried  on,  through 
Messrs.  Comstock  and  Slingerland,  a  valuable  series  of  experi- 
ments against  these  pests  extending  over  three  years,  with  the 
result  that  none  of  the  alleged  standard  remedies  produced 
satisfactory  effects.  In  short,  the  results  were  negative  rather 
than  positive,  and  no  single  method  has  yet  been  devised  by 
which  we  can  destroy  these  insects  as  we  can  most  other  pests. 
This  is  due  to  natural  causes — viz.,  to  the  hardness  and  con- 
sequent hardiness  of  wireworms,  two  qualities  which  go  hand 
in  hand  as  regards  insects  and  which  render  these  creatures 
almost  impervious  to  poisons  that  would  destroy  other  insects, 
and  to  the  fact  that  they  live  during  nearly  their  entire  active 
stage  as  wireworms  usually  rather  deeply  in  the  soil.  They 
require  two  or  three  years,  like  the  white  grubs,  for  full  matur- 
ity from  egg  to  adult. 


82  INSECTS    INJURIOUS    TO   VEGETABLES 

METHODS    OF   CONTROL 

No  application  that  can  be  made  to  the  soil  will  kill  the  wire- 
worms  without,  at  the  same  time,  rendering  the  land  unfit  for 
cultivation  for  some  time  afterward. 

Most  remedies,  preventives,  repellents  and  poisons  that  have 
been  tried  are  hardly  more  than  palliative.  From  among  these 
the  ones  that  give  most  promise  are  early  fall  plowing,  the  use 
of  poisoned  baits  early  in  the  season,  with  the  selection  of  un- 
infested  land  for  planting,  and  rotation  of  crops.  We  are  in 
fact  confronted  with  much  the  same  problems  as  in  the  treat- 
ment of  white  grubs,  only  wireworms  are  even  more  difficult 
of  suppression. 

Selection  of  land  for  planting— The  most  important  of  de- 
fensive methods  is  the  selection  of  the  land  for  planting. 
It  is  inadvisable  to  plant  crops  peculiarly  subject  to  wireworm 
attack,  such  as  corn,  potatoes,  and  other  vegetables,  as  well  as 
cereals  in  sod  land  or  in  unbroken  prairie,  and  it  is  equally 
unwise  to  cultivate  such  crops  in  fields  in  which  wireworms 
are  known  to  be  present. 

Fall  ploiving.—lnitsted  or  "suspicious"  soil  should  first  be 
prepared  for  the  crop  by  plowing  early  in  the  fall.  By  this 
process  the  cells  in  which  the  pupae  and  hibernating  adults  are 
resting  are  broken  up  and  the  insects  destroyed  in  great  num- 
bers, so  that  fewer  individuals  survive  to  deposit  eggs  for  an- 
other generation  of  wireworms  the  following  year.  Such  as 
are  not  destroyed  outright  by  this  method  will  be  more  exposed 
to  the  elements  and  to  predatory  enemies. 

Crop  rotation  should  also  be  practiced  in  the  same  manner 
as  prescribed  for  white  grubs.  In  addition  to  clover,  buckwheat 
is  said  to  be  a  valuable  alternate  because  of  the  roots  being  too 
tough  and  hard  to  be  injured,  and  possibly  this  is  true  of  some 
forms  of  wireworms,  but  not  of  all,  so  we  cannot  place  much 
reliance  on  this  crop.  If  clover  or  other  alternate  be  allowed 
to  remain  for  one  or  two  years  after  grass  has  been  cut,  veg- 


GENERAL    CROP    PESTS  83 

etables  subject  to  attack  can  then  be  planted  with  much  less 
danger  of  serious  infestation.  It  is  difficult  with  our  present 
knowledge  to  name  an  absolutely  immune  crop. 

Poisoned  baits. — An  efficacious  remedy  is  found  in  poisoned 
baits.  One  of  these  consists  in  sowing  corn,  soaked  in  water, 
containing  arsenic  or  strychnine,  over  the  field  about  ten  days 
before  the  crop  is  planted  and  then  harrowing  it  in.  The  larvae 
that  attack  the  poisoned  kernels  will  be  destroyed.  For  luring 
beetles,  as  well  as  larvae,  baits  of  sliced  potatoes  or  other  veg- 
etables, or  wads  of  succulent  vegetation,  such  as  clover,  or  pig- 
weed, or  sweetened  corn-meal  dough,  are  useful.  These  are 
poisoned  in  the  same  manner  as  the  corn  and  placed  about  the 
fields  under  boards  early  in  the  season.  These  traps  should  be 
renewed  as  often  as  possible.  Experiments  have  shown  the 
futility  of  starvation  of  wireworms  by  clean  fallowing. 

Although  these  remedies  are  not  infallible  against  wire- 
worms,  they  are  of  value  in  certain  sorts  of  soils  against  some 
species,  and  they  serve  in  a  manner  to  destroy  white  grubs  and 
cutworms  which  are  also  apt  to  be  present. 

APHIDES,    PLANT-BUGS     AND    RELATED    INSECTS 

Nearly  all  forms  of  plants  are  attacked  by  sucking  insects, 
the  aphides,  plant-bugs,  leafhoppers  and  numerous  related 
forms.  The  best  known  are  the  aphides  or  plant-lice,  many 
of  which  do  injury  to  vegetable  crops.  Among  other  insects 
which  obtain  nourishment  by  suction  are  several  species  of 
true  bugs  of  the  family  Capsidas,  generally  termed  plant-bugs, 
although  some  forms  are  also  known  as  leaf-bugs,  chinch  bugs, 
and  other  names  indicative  of  their  habits  or  appearance.  The 
commonest  and  most  injurious  of  these  insects  to  vegetables  are 
two  forms  of  false  chinch  bugs,  the  tarnished  plant-bug  and 
garden  flea-hopper.  The  thrips  also  obtain  their  food  by  suc- 
tion, and  for  convenience  may  be  included  in  the  same  category, 
although  they  are  not  closely  related  to  them  structurally. 


84  INSECTS    INJURIOUS    TO    VEGETATiLES 

Aphides  or  Plant-lice. — Nearly  every  one  knows  the  plant- 
lice  or  aphides,  since  there  are  few  succulent  plants  that  are 
exempt  from  their  attack.  Many  staple  crops  of  the  field, 
garden,  and  orchard  are  very  severely  damaged  when  these 
insects  multiply  in  unusual  numbers,  as  so  frequently  happens. 
Aphides  are  also  known  as  "lice,"  "aphis"  and  "green  fly." 

There  are  many  species,  as  varied  in  appearance  as  in  habits, 
and  although  they  have  attracted  attention  for  years  on  account 
of  the  injuries  which  they  cause  and  their  interesting  habits, 
they  are  perhaps  less  understood  than  any  large  group  of  insects 
which  could  be  named.  In  fact,  \vc  are  not  as  yet  able  to  estab- 
lish beyond  a  certain  degree  of  doubt  the  identity  of  some  of  our 
most  injurious  forms  and  we  know  less  of  their  life  economy. 

Gardens  are  seldom  free  from  their  attacks,  and  cabbage  and 
like  crops,  melons,  cucumbers  and  similar  plants,  peas  and  young 
budding  fruit  trees  suffer  severely  in  some  seasons. 

The  best-known  aphides  are  soft-bodied  and  green,  very 
minute  in  size,  with  long  legs  and  antennae.  Immense  masses 
of  them  frequently  congregate  on  single  plants,  sometimes  over- 
running entire  fields.  If  a  mass  be  closely  examined  it  will  be 
seen  that  many  are  wingless  during  the  greater  part  of  the 
season;  later,  however,  there  are  many  which  develop  wings 
and  are  capable  of  flight.  There  are  many  stages  of  these  in- 
sects, but  the  body  is  usually  formed  more  or  less  like  a  pear, 
and  the  winged  forms  have  two  pairs  of  very  delicate  trans- 
parent wings  with  a  few  simple  veins.  The  first  and  second 
pairs  of  wings  are  usually  connected  as  in  wasps  and  bees,  by 
a  booklet.  The  haustellum  or  beak  by  which  aphides  obtain 
their  food  is  three-jointed  and  of  variable  length.  The  eyes 
are  compound  and  project  prominently  at  the  sides  of  the  head. 
The  aphides  exude  "honey-dew,"  a  transparent  fluid  with 
a  sweetish  taste.  Frequently  it  is  excreted  in  such  quantity 
that  it  forms  a  shining  cover  to  the  leaves  of  plants.  The 
honey-dew  of  most  species  is  very  attractive  to  a  number  of 


GENERAL    CROP    PESTS 


85 


Other  insects — ants,  wasps,  bees  and  flies — and  in  the  fond- 
ness of  ants  for  this  substance  there  is  developed  a  curious 
inter-relationship. 

The  various  phases  of  development,  the  varieties  of   forms 
produced  by  some  genera,  in  fact,  the  life  economies  of  these 


Fig.  47-— Melon  aphis,  a.  Winged  female; 
oa.  enlarged  antenna  of  same;  ah,  dark 
female,  side  view;  b,  young  nymph  or 
larva  c.  last  stage  of  nymph;  d,  wingless 
female— all  greatly  enlarged.  (Author  s 
Illustration,  U.  S.  Dept.  Agr.) 


Fig.  48.— Flavescent  leaf- 
hopper  {Empoasca  flaves- 
cens).  Highly  magnified. 
(Author's  Illustration,  U.  S. 
Dept.  Agr.) 


insects  would  fill  several  volumes,  and  there  is  such  great 
diversity  of  habit  that  it  is  difficult  to  generalize. 

The  species  which  feed  upon  vegetable  crops  live  for  the  most 
part  on  the  under  surface  of  leaves ;  but  some  are  root-feeders, 
and  the  destructive  grape  phylloxera  is  an  example  of  one  of 
these  subterranean  forms  which  produce  galls. 

The  melon  aphis  (fig.  47)  is  one  of  our  commonest  and  best 
known  vegetable-feeding  forms  of  this  class. 

The  best  remedies  for  aphides  are  kerosene  emulsion,  fumiga- 
tion with  bisulphid  of  carbon  and  with  tobacco  extracts,  clean 
cultural  methods  of  farming  and  the  encouragement  of  natural 
enemies.    These  remedies  are  considered  on  pages  165  to  168. 

The  Leafhoppers. — Leafhoppers  are  familiar  to  nearly 
everyone,  although  not  everybody  knows  them  by  this  name. 


86  INSECTS    INJURIOUS    TO    VEGETABLES 

As  we  walk  over  lawns  and  through  meadows  and  pastures 
generally,  particularly  in  midsummer  and  later,  myriads  of 
these  minute  creatures  fly  up  and  are  sometimes  annoying  by 
getting  into  our  faces  and  even  our  eyes.  Recently  their  true 
economic  value  has  been  ascertained,  and  this  was  brought 
about  mainly  through  the  studies  of  Prof.  Herbert  Osborn,  in 
Iowa.  They  are  most  numerous  in  grasses  from  which  they 
drain  the  vitality  by  sucking  the  sap  from  the  blades.  It  has 
been  estimated  that  between  one-fourth  and  one-half  of  all  the 
grass  growing  annually  is  destroyed  by  leafhoppers,  a  startling 
statement  but  borne  out  by  actual  observation.  Although  most 
of  these  insects  feed  on  grasses,  there  are  some  which,  partic- 
ularly in  their  later  stages  as  nymphs  and  as  adults,  attack 
various  vegetables  and  other  plants.  Leafhoppers  are  mostly 
small,  some  very  minute  and  slender,  with  short  heads  more  or 
less  crescent-shaped,  and  with  long  hind-legs  which  fit  them  for 
jumping.  They  also  have  long  wings  and  are  strong  flyers. 
The  species  illustrated  (fig.  48)  attacks  a  variety  of  vegetables. 

In  their  attacks  on  plants  the  usual  method  is  to  puncture  the 
cells  from  the  under  side  of  the  leaves,  causing  yellowish, 
brownish  or  other  discolored  spots  to  appear  later.  When 
punctures  are  numerous  entire  leaves  wilt  and  die.  A  few  forms 
attack  culinary  vegetables  by  preference,  but  most  others  occur 
on  different  plants.  No  less  than  thirty  distinct  species  have 
been  found  on  beets. 

Methods  of  Control. — Several  methods  have  been  devised 
for  keeping  leafhoppers  in  subjection.  The  standard  remedies 
are  kerosene-soap  emulsion  and  sprays  of  soap.  An  underspray- 
ing  is  always  necessary.  The  spray  should  be  as  fine  as  possible, 
and  applied  upon  the  first  appearance  of  the  insects,  not  only  to 
produce  the  best  effect,  but  because  by  using  it  early  in  the 
spring  the  insects  may  be  prevented  from  developing  in  large 
numbers  later  in  the  season,  for  with  many  forms  there  are  two 
and  sometimes  three  generations  produced  annually. 


GENERAL    CROP    PESTS  8/ 

Leafhoppers  may  also  be  captured  on  sticky  surfaces,  and 
one  good  way  of  destroying  them  in  small  gardens  is  by  causing 
them  to  fly  up  and  capturing  them  on  large  frames  coated  with 
sticky  substances  such  as  coal  tar.  If  this  method  is  persisted  in 
for  several  days  few  of  the  insects  will  be  left,  as  they  are 
readily  caught.  A  good  time  for  this  work  is  just  before  sun- 
down. Special  hopper-dozers  are  used  for  leafhoppers,  similar 
to  those  described  as  grasshopper  destroyers  (page  71).  Some 
of  these  are  termed  "hopperettes." 

The  Tarnished  Plant-bug  (Lygus  pratensis  Linn.).— This  bug 


Fig.  49  —Tarnished  plant-bug.    Adult  at  left:  last  stage  of  nymph  at  right 
(Author's  Illustration.  U.  S.  Dept.  Agr.) 

is  one  of  the  most  troublesome  of  its  kind.  It  is  found  prac- 
tically everywhere  in  North  America,  and  attacks  many  plants, 
cultivated  and  wild.  It  occurs  throughout  the  warm  season,  and 
frequently  does  damage  to  vegetables  and  to  trees  grown  in 
nurseries.  The  mature  plant-bug  (fig.  49)  is  of  nearly  elliptical 
form,  and  considerably  flattened.  The  head  is  nearly  triangular, 
with  the  eyes  showing  prominently  at  the  sides.  It  is  pale, 
obscure,  grayish  brown,  marked  with  black  and  yellow,  the 
thorax  also  with  red.  The  length  is  about  one-fifth  of  an  inch. 
With  little  doubt  this  plant-bug  has  five  stages  of  the  nymphs 
to  agree  with  related  species  which  have  been  traced  through 
their  metamorphoses.    The  first  stage  measures  only  about  one- 


88  INSECTS    INJURIOUS   TO   VEGETABLES 

twentieth  of  an  inch,  and  is  yellowish  green.  This  species  is 
quite  injurious  to  cabbage,  turnip,  potato  and  cucumber,  and 
attacks  also  salsify  and  celery.  The  principal  injury  is  ac- 
complished in  the  spring,  by  the  adults  piercing  and  sucking 
the  juices  from  flowers  and  leaf-buds,  and  later  by  attacking 
tender  fruits  and  shoots. 

The  tarnished  plant-bug  is  credited  with  being  the  author  of 
"buttoning"  of  strawberries,  and  forms  of  "blight,"  the  insect 
in  the  latter  case  acting  as  a  transmitter  of  germs  from  dis- 
eased to  healthy  plants.  Were  it  not  that  this  plant-bug  dis- 
tributed its  attack  by  feeding  on  a  variety  of  crops  and  weeds, 
it  would  be  more  injurious  than  it  is.  The  bugs  are  extremely 
active,  quick  of  flight  as  well  as  of  foot,  and  when  disturbed 
have  the  habit,  in  common  with  kindred  species,  of  hiding  by 
dodging  to  the  opposite  side  of  a  plant.  Hibernation  is  usually 
in  the  adult  stage.  In  early  spring,  the  females  deposit  their 
eggs  singly  on  plants,  continuing  for  two  weeks  or  longer. 
According  to  Prof.  J.  M.  Stedman,  three  generations  develop 
in  southern  Missouri,  and  two  in  the  northern  portion  of  that 
state.  The  duration  of  the  life  cycle  may  be  placed  approx- 
imately at  about  four  weeks,  or  a  little  longer,  the  length  of 
time  depending  on   season   and   climate. 

Remedies. — The  standard  bug  remedy,  kerosene  emulsion,  is 
the  best,  sprayed  on  as  thoroughly  as  possible  to  all  crop  plants 
as  well  as  weeds  attacked.  Pyrethrum  is  of  value,  but  must  be 
applied  repeatedly  and  is  rather  expensive.  Hand  methods  are 
also  valuable,  and  a  hand  net  is  useful  for  sweeping  the  plants 
and  surrounding  grass  and  other  vegetation.  Frequently  more 
individuals  can  be  captured  in  this  way  than  in  any  other. 
When  a  considerable  number  have  been  taken,  they  can  be  killed 
by  throwing  them  into  large  pans  of  water  with  a  few  drops 
of  kerosene.  After  the  crop  is  off  "back  firing"  should  be 
practiced  in  the  same  manner  as  described  as  a  remedy  for 
army  worms  on  page  58. 


GENERAL    CROP    PESTS 


89 


The  Onion  Thrips  (Thrips  tabaci  Lind.). — Few  gardeners 
are  unacquainted  with  "thrips,"  of  which  there  are  several 
species  injurious  to  plants  grown  under  glass.  The  commonest 
and  most  destructive  vegetable-feeding  species  in  America  are 
the  onion  thrips  and  the  wheat  thrips. 

All  thrips  are  exceedingly  minute,  the  common  species  not 
exceeding   one-twentieth    of    an    inch    in    length.      They    have 


Fig.  50. — Onion  thrips.     a,  Adult;  b,  antenna  of  same;  c,  young  larva;  d,  fuU-grovm 
larva— greatly  enlarged.    (Howard,  U.S.  Dept.  Agr.) 


elongate  bodies,  and  the  winged  lorms  have  four  very  slender 
wings  fringed  with  long,  delicate  hairs.  These  insects  are 
somewhat  anomalous  in  the  manner  of  their  feeding:  their 
mouth-parts  are  fitted  chiefly  for  sucking,  but  they  also  have 
bristle-like  mandibles. 

The  general  appearance  of  the  onion  thrips  is  shown  in 
figure  50,  Oj  highly  magnified.  It  is  pale  yellow,  with  the  thorax 
somewhat  darker.  The  wings  are  paler  yellow,  with  dusky 
fringes  and  bristles. 

The  parent  insects  are  usually  found  on  the  lower  sides  of 
leaves  or  imbedded  in  flowers  of  various  kinds.  In  their  attacks 
they  induce  the  withering  of  the  parts  affected,  and  they  some- 
times destroy  entire  plantings.  The  onion  thrips  injures  a  great 
variety  of  field  and  garden  crops,  to  which  it  is  quite  as  de- 
structive as  to  plants  grown  artificially.  Besides  onion  it  in- 
juriously affects  garden  leek,  parsley,  cabbage,  celery,  melon, 


90  INSECTS    INJURIOUS    TO   VEGETABLES 

cucumber,  squash,  turnip,  cauliflower  and  strawberry,  and  does 
more  or  less  damage  to  nasturtium,  mignonette,  carnations, 
candytuft,  four-o'clock  and  rudbeckia. 

The  female  thrips  cuts  a  slit,  in  a  leaf  or  stem  usually,  to 
deposit  her  eggs.  In  a  few  days  the  young  thrips  work  their 
way  out  and  begin  to  feed.  They  suck  the  juices  of  plants  and, 
as  they  feed  continuously,  their  growth  is  rapid.  The  entire 
life  cycle  from  the  time  of  the  deposition  of  the  eggs  until  the 
maturing  of  the  adult  is  passed  under  favorable  coalitions,  in 
a  warm  atmosphere,  in  three  weeks.  Out-of-doors  in  a  cooler 
atmosphere  a  longer  period  would  be  required  for  the  life  cycle. 

The  minute  size  of  thrips,  with  their  habits  of  feeding  by 
suction,  in  concealment  in  their  host  plants,  renders  it  difficult 
to  treat  them  successfully.  The  best  contact  poisons  are  dilute 
kerosene-soap  emulsion,  applied  as  for  aphides  (p.  361).  It 
is  practicable  in  some  cases  to  dip  whole  plants,  when  being 
transferred  from  the  hothouse  to  the  field,  in  kerosene 
emulsion. 

For  fumigation,  hydrocyanic-acid  gas,  carbon  bisulphid  and 
different  preparations  of  tobacco  are  useful.  Tobacco  prepara- 
tions, containing  about  40  per  cent,  nicotine,  have  been  found 
effective  at  the  rate  of  5  or  6  teaspoonfuls  to  i  J/2  pints  of  water 
when  vaporized  in  a  space  of  5,000  cubic  feet.  This  method  does 
not  injure  cucumbers  w^hile  nearly  all  the  thrips  on  plants  thu, 
treated  are  killed. 

In  the  field  drenching  affected  plants  with  a  hose  will  kill 
many  of  the  pests.  Clean  methods  of  farming  is  a  necessity, 
as  thrips  develop  largely  in  grasses,  weeds  and  other  vege- 
tation in  and  near  onion  fields.  All  other  infested  plants  should 
also  be  treated  with  kerosene-soap  emulsion,  and  the  weeds 
burned  where  possible. 

The  Wheat  Thrips  {Thrips  tritici  Fitch).— This  native  spe- 
cies, also  called  the  strawberry  midget,  has  been  reported  as 


GENERAL    CROP    PESTS 


91 


doing  injury  to  parsley,  pea,  endive,  cotton,  orchard  and  small 
fruits  and  roses.  Its  color  is  yellow,  with  the  thorax  tinged 
with  orange,  and  the  antennx  or  feelers  are  ringed  with  a  dusky 
color  (fig.  15)-  It  is  distributed  from  Canada  to  Florida,  and 
westward. 

Remedies. — The  same  as  for  the  onion  thrips. 
The    Red    Spider    {Tetranychus    bimacidatus    Haw.). — Few 
vegetables  are  free  from  the  attacks  of  red  spider   (fig.  50jr). 

These  creatures  are  extremely 

minute,     and     are     frequently 

not  noticed  until  they  become 

excessively  numerous,  as  hap- 
pens during  summer  droughts. 

They  do  considerable  damage 

in    vegetable    gardens    and    to 

plants  grown  under  glass. 

Remedies. — Flowers  of  sul- 
phur, mixed  with  water  at  the 

ration    of    one    ounce    to    the 

gallon,   and   sprayed   over   the 

plants,    is    of    great    value    in 

eradicating  this  pest.     Fish-oil 

and  other   soap   solutions   are  P's-  50x.-Red  spider,   a,  Adult;  b.  palpus-, 

c,  claws.    (After  Banks,  U.  S.  Dept.  Agr.) 

valuable,  and  the  addition  of 

sulphur  increases  their  effectiveness,  but  are  too  strong  for 
some  delicate  plants.  Greenhouse  plants  are  sprayed  with 
water  two  or  three  times  a  week  during  the  growing  season, 
and  care  is  exercised  to  wash  off  the  spiders  and  not  drench 
the  beds. 


Fig.  51 


-Spray  of  asparagus,  with  common  asparagus  beetle  in  different  stages 
Natural  size.    (Author's  illustration,  U.  S.  Dept.  Agr.) 


92 


CHAPTER   VI 


INSECTS  INJURIOUS  TO  ASPARAGUS 

Asparagus  was  introduced  into  America  with  the  early  settlers 
from  Europe,  and  was  cultivated  here  for  two  hundred  years 
before  being  troubled  with  insects.  Few  edible  plants  down  to 
the  time  of  the  Civil  War  have  enjoyed  such  immunity  from  the 
ravages  of  insects.  The  principal  insect  enemies  of  asparagus 
are  two  leaf-beetles,  both  imported  from  the  Old  World,  and 
limited  for  food  supply  to  this  plant. 

The  Common  Asparagus  Beetle  (Crioceris  asparagi  Linn.), 
as  its  English  name  indicates,  is  the  more  abundant  asparagus 


Fig.  52.— Common  asparagus  beetle,     a.  Beetle;  b,  egg;  c,  newly-hatched  larva;  d, 
full-grown  larva;  e,  pupa— all  enlarged.    (Author's  illustration) 

beetle  and  by  far  the  most  important  foe  of  this  plant.  Its  first 
appearance  was  noted  in  this  country  at  Astoria,  near  New 
York  City,  in  i860,  where  it  was  introduced  about  1856. 

The  injury  inflicted  by  this  insect  is  due  to  the  work  of  both 
adults  and  larvae  upon  the  tender  shoots,  which  they  render 
unfit  for  market  early  in  the  season.  Later  they  destroy  by 
defoliation  growing  plants,   and   are   particularly   injurious   to 

93 


94  INSECTS    INJURIOUS   TO   VEGETABLES 

seedlings,  the  roots  of  which  are  weakened  by  having  their  tops 
devoured.  Larvas,  as  well  as  beetles,  attack  the  tenderest  por- 
tions of  the  plants,  but  the  latter  gnaw  with  seemingly  equal 
relish  the  epidermis,  or  rind,  of  the  stems. 

The  beetle,  illustrated  by  figure  52,  is  a  most  beautiful  creature, 
slender  and  graceful  in  form,  blue-black  in  color,  with  red 
thorax,  and  lemon-yellow  and  dark-blue  elytra  or  wing-covers, 
with  reddish  border.  Its  length  is  a  trifle  less  than  one-fourth 
of  an  inch. 

From  the  scene  of  its  first  colonization,  Queens  County,  N.  Y., 
the  insect  migrated  to  other  truck-growing  regions,  and  has 
now  extended  its  range  northward  through  Connecticut  and 
Massachusetts  to  the  State  line  of  New  Hampshire.  Southward 
it  has  traveled  to  southern  Virginia.  At  the  present  time  it  is 
well  established  in  the  principal  asparagus-growing  sections  of 
the  northern  Atlantic  region,  and  occurs  westward  to  Illinois 
and  Michigan.  In  a  very  few  years  we  may  expect  its  spread 
to  other  portions  of  states  in  which  it  is  now  local,  and  later 
it  will  naturally  move  westward. 

The  insect  passes  the  winter  in  the  beetle  state  under  con- 
venient shelter,  and  in  April  or  May,  according  to  locality,  or 
at  the  season  for  cutting  asparagus,  issues  from  its  hibernating 
quarters  and  lays  its  eggs  for  the  first  brood.  The  eggs  are 
deposited  endwise  upon  the  stem  or  foliage  and  in  early  spring 
on  the  developing  stalks,  in  rows  of  from  two  to  six  or  more. 

In  from  three  to  eight  days  the  eggs  hatch,  the  young  larvae, 
"grubs"  or  "worms,"  presenting  the  appearance  indicated  in 
figure  52,  c.  They  at  once  begin  to  feed,  and  are  from  ten  days 
to  a  fortnight  in  attaining  full  growth.  When  full  grown  the 
larva  appears  as  in  figure  52,  d.  It  is  soft  and  fleshy,  and  in 
color  is  dark-gray  or  olive,  which  becomes  lighter  and  yellowish 
with  age.  The  mature  larva  enters  the  earth,  and  here,  within 
a  little  rounded,  dirt-covered  cocoon  which  it  forms,  the  pupa 
state  is  assumed.    In  from  five  to  eight  or  more  days  the  beetle 


INSECTS    INJURIOUS    TO    ASPARAGUS  95 

is  produced,  which  issues  from  the  ground  in  search  of  food 
and  of  a  suitable  place  for  the  continuance  of  the  species.  The 
duration  of  the  life  cycle,  according  to  Fitch,  is  about  thirty 
days  from  the  time  the  egg  is  laid  until  the  insect  attains  matur- 
ity. In  the  District  of  Columbia  the  eggs,  in  the  warmest  part 
of  midsummer,  develop  in  three  and  the  pupae  in  five  days.  In 
the  present  range  of  the  species  two  and  perhaps  three  broods 
are  usually  produced.  The  beetles  enter  into  hibernation  in 
September. 

The  asparagus  beetle  has  efficient  checks   in  predaceous  in- 
sects,  which  prey  upon  its  larvae  and  assist   in   preventing  its 
undue  increase.    Among  these  are  the  spotted  ladybird  (Mcgilla 
macnlata    DeG.),    the    spined 
soldier-bug     (Podisus    niacidi- 
vintris  Say)   and  the  bordered 
soldier-bug   {Stirctnis  anchor- 
ago    Fab.,    fig.     53).      Wasps 
and    small    dragon    flies    also 
prey    upon    the    larvae.       Im- 
mense numbers  of  beetles  are 
sometimes  killed  in  winter  dur- 

,  ,  „       f   ,.  Fig.  53.— Bordered  soldier-bug.     Enlarged 

mg    severe    cold    spells    follow-        (Author's  illustration,  U.  S.  Dept.  Agr.) 
ing  "open"  weather. 

Remedies. — The  common  asparagus  beetle,  under  ordinary 
circumstances,  may  be  held  in  restraint  by  the  simplest  means. 

Chickens  and  ducks  are  efficient  destroyers  of  them,  and  their 
services   are   often   brought   into   requisition   for   this   purpose. 

A. practice  in  high  favor  is  to  cut  down  all  plants,  including 
volunteer  growth,  in  early  spring  to  force  the  beetles  to  deposit 
their  eggs  upon  new  shoots,  which  are  then  cut  every  few  days 
before  the  eggs  hatch.  Another  measure  of  value  consists  in 
permitting  a  portion  of  the  shoots  to  grow  and  serve  as  lures 
for  the  beetles.  Here  they  are  killed  with  insecticides,  or  the 
plants  after  they  become  covered  with  eggs  are  cut  down  and 
burned,  and  other  shoots  are  allowed  to  grow  up  as  decoys. 


96  INSECTS    INJURIOUS    TO    VEGETABLES 

One  of  the  best  remedies  against  the  larvae  is  fresh,  air-slaked 
lime  dusted  on  the  plants  in  the  early  morning  while  the  dew 
is  on.  It  quickly  destroys  all  the  grubs  with  which  it  comes 
in  contact. 

The  arsenicals,  applied  dry  in  powder  mixed  with  lime,  an- 
swer well,  and  possess  the  advantage  of  destroying  beetles  as 
well  as  grubs,  and  are  of  value  upon  plants  that  are  not  being 
cut  for  food.  To  produce  satisfactory  results  the  lime  or  arsenite 
must  be  applied  at  frequent  intervals,  or  as  often  as  the  larvae 
reappear  on  the  beds.     Arsenate  of  lead  is  an  excellent  remedy. 

A  simple  method  of  killing  the  larvae  in  hot  weather  is  to 
brush  them  from  the  plants  so  that  they  will  drop  to  the  heated 
earth,  where  they  die  before  being  able  to  return. 

The  Twelve-spotted  Asparagus  Beetle  {Crioceris  12-punctata 
Linn.). — The  chief  source  of  damage  from  this  species  is  from 
the  work  of  the  hibernated  beetles  in  early  spring  on  young  and 
edible  asparagus  shoots.  Later  the  beetles  as  well  as  larvae  ap- 
pear to  feed  exclusively  on  the  berries.  The  eggs  are  deposited 
singly,  and  apparently  by  preference,  on  old  plants  toward  the 
ends  of  shoots,  which,  lower  down,  bear  ripening  berries,  and 
they  are  attached  along  their  sides  instead  of  at  one  end,  as 
with  the  common  species.  Soon  after  the  larva  hatches  from 
the  tgg  it  finds  its  way  to  an  asparagus  berry,  enters  it,  and 
feeds  upon  the  pulp.  In  due  time  it  leaves  this  berry  for  an- 
other one,  and  when  full  growth  is  attained  it  deserts  its  last 
habitation  and  enters  the  earth,  where  it  transforms  to  pupa 
and  afterwards  to  the  beetle.  The  life  cycle  does  not  differ 
materially  from  that  of  the  common  species,  and  there  are 
probably  as  many  generations  developed. 

This  species  is  at  present  distributed  throughout  nearly  the 
same  territory  of  the  North  as  the  preceding.  The  beetle  rivals 
the  common  asparagus  species  in  beauty,  but  may  be  distin- 
guished by  its  much  broader  wing-covers  and  color.  It  is  orange 
red,  and  each  wing-cover  is  marked  with  six  black  dots,  and  the 
knees  and  a  portion  of  the  under  surface  of  the  thorax  are  also 


INSECTS    INJURIOUS   TO   ASPARAGUS 


97 


marked  with  black  (fig.  54,  a).    The  beetle  as  it  occurs  on  plants 
when  in  fruit  very  closely  resembles,  at  a  little  distance,  a  ripe 
asparagus  berry. 
The  full-grown  larva  is  shown  at  figure  54,  b.     It  measures. 


Fig  54 —Twelve-spotted  asparagus  beetle,  a.  Beetle;  b,  larva;  c,  second  abdominal 
segment  of  larva;  d  same  of  common  asparagus  beetle,  a,  b.  Enlarged;  c,  <4  more 
enlarged     (Chittenden.  U  S  Dept.  Agr.) 


when  extended,  three-tenths  of  an  inch,  being  of  about  the  same 
proportions  as  the  larva  of  the  common  species,  but  is  readily 
separable  by  its  ochraceous  orange  color.  ■' 

Remedies  are  those  indicated  for  the  common  asparagus 
beetle,  with  the  exception  of  caustic  lime  and  other  measures 
that  are  directed  solely  against  that  species,  but  the  habit  of 
the  larva  of  living  within  the  berry  places  it  for  that  period 
beyond  the  reach  of  insecticides. 

The  Asparagus  Miner  {Agromyaa  simplex  Loew.).. — Aspara- 
gus stalks  are  sometimes  considerably  injured  by  a  maggot 
(fig.  55.r,  a)  which  mines  under  the  skin  near  or  just  beneath 
the  base.  The  appearance  of  the  afifected  stalk  (/)  is  charac- 
teristic.    The  parent  insect  is  a  small  black  fly. 

Remedial  Suggestions. — Permit  a  few  volunteer  asparagus 


98 


INSECTS    INJURIOUS   TO   VEGETABLES 


plants  to  grow  as  traps  to  lure  the  female  fly  to  deposit  her 
eggs      Afterward,   in   late   June   or   early   July,   pull   the   trap 


Fig.  55.— Crioceris  12- 
pundata.  Egg.  natur- 
al size,  on  asparagus, 
right;  enlarged  at  left. 
(Chittenden,  U.  S. 
Dept.  Agr.) 


f 

Fig.  55x.— Asparagus  miner,  a.  Larva;  b,  c, 
spiracles;  d.  e,  puparium,  f.  section  of  asparagus 
stalk,  showing  injury  and  puparia.  a-e.  Much 
enlarged;  /,  slightly  reduced.  (Author's  illus- 
tration. U.S.  Dept.  Agr.) 


plants  and  promptly  burn  them  with  their  contained  insects  (in 
the  flaxseed  stage,  fig.  55.r,  d,  c). 

If  this  is  carefully  done  over  a  considerable  area,  there 
will  be  little  necessity  for  other  methods,  as  few  insects  will 
be  left  for  another  season ;  unless,  indeed,  this  insect  has  an 
alternate  food  plant.  Cooperation  and  thoroughness  are  essen- 
tials for  success.  This  method  will  operate  also  against  the 
rust  which  is  often  present  in  fields  infested  by  the  miner. 


CHAPTER   VII 


INSECTS  INJURIOUS  TO  BEANS  AND  PEAS 

Edible  legumes  are  subject  to  injury  by  certain  weevils, 
which  deposit  their  eggs  upon  or  within  the  pods  on  the  grow- 
ing plants  and  develop  within  the  seed.  The  specific  enemy  of 
the  pea  is  the  pea  weevil,  and  of  the  bean,  the  common  bean 
weevil,  both  of  sufficiently  wide  distribution  and  abundance  to 
hold  high  rank  among  injurious  insects.  The  inroads  of  these 
weevils  in  seeds  cause  great  waste,  and  particularly  is  this  true 
of  seed  kept  in  store  for  any  considerable  time.  In  former 
times  popular  opinion  held  that  the  germination  of  leguminous 
food  seed  was  not  impaired  by  the  action  of  the  larval  beetle  in 
its  interior,  but  this  belief  is  erroneous,  as  will  be  shown  in  the 
discussion  of  the  nature  of  the  damage  by  the  pea  weevil. 

Although  it  is  not  probable  that  any  serious  trouble  follows 
the  consumption  by  human  beings  of  the  immature  weevils  in 
green  peas  or  beans,  the  use  for  food  of  badly  infested  dry 
seed  filled  with  the  dead  bodies  and  excrement  of  the  beetles 
would  naturally  be  attended  with  unpleasant  consequences. 

Growing  pods  in  the  fields  are  invaded  by  the  bollworm  and 
pea  moth,  and  the  foliage  i^  preyed  upon  by  numerous  insects. 
Of  foliage  feeders  are  the  bean  leaf-beetle,  bean  ladybird, 
blister  beetles,  cutworms,  and  other  caterpillars.  Several  forms 
of  plant-bugs,  leafhoppers,  and  aphides  also  exhaust  the  plants 
by  sapping  their  juices. 

The  Pea  Weevil  (Bruchiis  pisorum  Linn.). — Seed  peas  are 
often  found  with  a  single  round  hole  in  them,  due  to  the  attack 
of  the  pea  weevil  or  "pea  bug,"  the  largest  of  the  pea  and  bean- 

99 


lOO  INSECTS    INJURIOUS   TO   VEGETABLES 

feeding  weevils  found  in  this  country,  measuring  about  a  fifth 
of  an  inch  in  length.  Its  ground  color  is  black,  but  it  is  thickly 
covered  with  brown  pubescence,  variegated  with  black  and 
white  markings  arranged  as  illustrated  in  figure  57,  a. 

®In  1748  the  celebrated  Swedish  naturalist  Pehr 
Kalm    gave    an    account    of    this    weevil,    stating 
that  the  culture  of  the  pea  had  been  abandoned  in 
Fig.    5  6. -A     Pennsylvania,    New    Jersey,    and    southern    New 
buggy  pea         York  on  account  of  it. 

There  are  reasons  for  believing  that  this  species  came  orig- 
inally, with  so  many  other  injurious  insects  which  live  upon 
cultivated  seeds,  from  the  Orient,  and  it  has  now  become  dis- 
tributed over  nearly  the  entire  globe,  wherever  peas  are  culti- 
vated. It  does  comparatively  little  damage  in  the  colder  parts 
of  Canada;  hence,  seed  peas  for  planting  in  the  United  States 
are  largely  imported  from  Canada  or  are  bought  from  seed 
dealers  who  obtain  them  from  our  more  northern  states. 


Fig.  57.— Pea  weevil    a.  Adult  beetle;  b.  larva;  c,  pupa.  All  greatly  enlarged 
(Author's  illustration,  U.  S.  Dept.  Agr.) 


Nature  of  injury. — Every  pea  in  a  pod  is  sometimes  infested 
with  this  weevil ;  and  although  nearly  every  one  is  familiar  with 
"buggy"  peas,  it  is  not  generally  known  that  in  eating  green 
peas  we  often  eat  also  a  "worm"  with  nearly  every  pea.  The 
only  external  evidence  of  infestation  in  a  green  pea  is  a  minute 


INSECTS    INJURIOUS    TO    BEANS    AND    PEAS  lOI 

dot  on  its  surface,  but  in  dry  seed  the  cell  inhabited  by  the 
insect  is  visible  under  the  skin. 

The  belief  was  once  more  or  less  prevalent  that  the  larva 
working  within  the  seed,  by  some  wonderful  instinct,  avoided 
the  germ  or  embryo,  and  that  weevil-infested  peas  were  there- 
fore of  equal  value  for  seed  to  uninfested  ones,  but  this  is  in- 
correct. Many  "weeviled"  seed  will  germinate,  but  as  they  are 
deficient  in  plant  food  the  resulting  plant  is  apt  to  be  weakly 
and  nonproductive. 

This  species  develops  only  a  single  generation  annually.  As 
it  does  not  breed  in  dry  peas,  the  new  generation  for  another 
year  is  dependent  on  such  beetles  as  are  contained  in  planted 
seed  or  which  escape  from  the  storeroom. 


Holding  over  seed. — A  simple  and  effective  remedy  consists 
merely  in  keeping  seed  peas  in  a  close  receptacle,  a  tight  bag 
or  box,  over  one  season  before  planting.  The  beetles  which 
issue  die  without  being  able  to  lay  their  eggs  in  the  field. 
Primary  injury  to  the  seed  has  been  effected  by  the  larva  the 
first  summer  and  after  the  weevil  develops,  always  during  the 
first  autumn  in  the  writer's  experience,  further  damage  prac- 
tically ceases. 

Late  planting. — Comparative  immunity  from  pea  weevil  at- 
tack is  claimed  in  some  localities,  c.  g.,  in  the  southern  states, 
by  planting  late,  and  is  all  that  is  necessary  to  secure  sound 
seed  stock. 

Bisulphid  of  carbon. — When  it  is  desired  to  plant  the  first 
season  after  gathering  the  seed,  bags  in  which  peas  have  been 
kept  tightly  closed  should  be  placed  in  a  tight  box  or  vessel  and 
disinfected  with  bisulphid  of  carbon,  at  the  rate  of  an  ounce 
or  two  to  100  pounds  of  seed.    This  method  will  kill  the  weevils 


I02 


INSECTS    INJURIOUS   TO   VEGETABLES 


Fig.  58.— Common  bean  weevil. 
Greatly  enlarged.  (Author's 
illustration.  U.  S.  Dept.  Agr.) 


without  injury  to  the  germinative  property  of  the  seed.  A 
similar  remedy  consists  in  soaking  infested  seed  for  one  minute 
in  boiling  water.    A  longer  time  is  apt  to  injure  it  for  planting. 

No  efficient  preventive  of  in- 
jury is  known,  but  cooperation 
in  the  treatment  of  infested  seed 
would  render  further  action  un- 
necessary. 

The  Common  Bean  Weevil 
(Bruchus  obtectus  Say). — The 
most  formidable  enemy  to  the 
culture  of  beans  is  the  common 
bean  weevil.  In  the  nature  of 
its  attack  it  differs  from  the 
pea  weevil  in  that  it  not  only 
develops  in  the  pods  in  the  field 
but  continues  to  breed  for  suc- 
cessive generations  in  seed,  after  harvest  and  storage,  until  the 
seed  is  useless  for  planting  or  as  food  for  man  or  stock. 

As  with  peas,  the  market  gardens  of  the  North  provide  the 
dry  seed  for  consumption  and  for  planting  in  the  Southern 
States.  In  and  about  Washington,  D.  C,  it  is  next  to  impos- 
sible to  procure  a  crop  of  beans  uninfested  by  this  weevil; 
hence,  the  stores  of  the  city  are  supplied  mainly  from  the  North, 
New  York  State  furnishing  the  greatest  quantities. 

This  bean  weevil  is  smaller  than  the  preceding,  averaging 
about  an  eighth  of  an  inch  in  length.  It  is  coated  with  fine 
brown-gray  and  olive  pubescence  which  gives  the  body  that  col- 
or. The  wing-covers  are  mottled,  as  shown  in  figures  58  and  60. 
From  the  pea  weevil  this  species  may  be  known  by  the  different 
shaped  thorax  and  the  two  small  teeth  in  addition  to  the  large 
tooth  with  which  the  thighs  are  armed.  In  figure  60,  a,  the  beetle 
is   represented  in  profile   with   its   head   bent   under   in   natural 


INSECTS    INJURIOUS    TO    BEANS   AND    PEAS 


103 


resting  position.  Until  recently  this  species,  like  the  preceding, 
was  generally  believed  to  be  indigenous.  It  is  certainly  not 
native  to  the  United  States,  and  if  introduced  from  the  Eastern 
Hemisphere  probably  became  acclimated  in  tropical  America 
before  establishing  itself  in  the  North.     Its  distribution  is  now 


Fig.  59.— Bean 
showing  injury 
by  common  bean 
weevil.  (From 
Riley.) 


Fig.  60.— Bean  weevil,  a.  In  profile;  b,  section  of 
bean-pod  showing  slit  for  egg  deposit;  c,  portion  of 
interior  of  pod  showing  egg  mass  inserted  through 
slit,  a,  c,  Much  enlarged.  (Reengraved  from 
Riley,  U.  S.  Dept.  Agr.) 


world-wide.  It  occurs  in  nearly  every  State  and  Territory  of 
the  Union,  and  is  generally  diffused  through  Central  and  South 
America. 

Oviposition  takes  place  primarily  in  the  field,  the  eggs  being 
deposited,  as  with  the  pea  weevil,  upon  or  inserted  in  the 
pod  through  a  hole  made  by  the  female  and  through  openings, 
such  as  are  caused  by  its  drying  and  splitting.  In  shelled  beans 
the  eggs  are  dropped  loosely  in  the  receptacle  in  which  they 
are  stored,  or  are  placed  in  holes  made  by  the  weevils  in  their 
exit  from  the  seed.  Less  seldom  they  are  attached  to  the  outer 
surface  of  the  seed. 

There  are  probably  produced  annually  an  average  of  six 
generations  in  latitudes  such  as  the  District  of  Columbia  and 
a  less  number  in  more  northern  localities.  Unlike  the  pea 
weevil,  a  large  number  of  individuals  will  develop  in  a  bean, 
as  many  as  twenty-eight  having  been  found  in  a  single  seed. 


104  INSECTS    INJURIOUS    TO   VEGETABLES 

Any  single  indoor  generation  is  capable  of  exhausting  seed  and 
completely  ruining  it  for  food  or  planting  or  any  other  practical 
purpose.  The  beetles  begin  to  issue  in  the  field  in  a  climate  like 
that  of  the  District  of  Columbia  as  early  as  October,  when  in 
the  natural  course  of  events  the  eggs  for  a  new  brood  would 
be  deposited  in  such  pods  as  had  cracked  open  so  as  to  expose 
the  seeds  within.  This  beetle  prefers  the  bean  as  a  host  plant, 
but  it  will  also  breed  in  cowpeas  in  the  field  as  well  as  in  store, 
and  in  confinement  develops  in  dried  peas,  lentils,  and  chick- 
peas. It  is  no  more  true  of  seed  infested  by  this  species  than 
of  that  attacked  by  the  pea  weevil  that  germination  is  not  im- 
paired by  the  work  of  the  weevil  in  the  bean.  Weeviled  beans 
should  not  be  planted.  In  a  test  only  50  per  cent,  of  the  infested 
seed  used  germinated,  and  only  30  per  cent,  could  have  passed 
the  germinating  stage,  and  these,  owing  to  injury  to  the  seed 
leaves,  would  probably  have  produced  plants  of  low  vigor  and 
correspondingly  low  productiveness. 

Remedies.— From  the  fact  that  this  species  breeds  continuously 
in  dried  seed,  neither  the  expedient  of  holding  over  seed  for 
a  year  before  planting  nor  that  of  planting  late  for  seed  stock 
would  be  productive  of  good,  as  in  the  case  of  the  pea  weevil. 
Recourse  must  therefore  be  had  to  fumigation  or  to  heat,  and 
the  earlier  the  seed  is  treated  after  it  has  been  gathered  the 
better  the  result.  Just  before  it  is  planted  seed  infested  with 
this  bean  weevil  should  be  lightly  thrown  into  water.  Badly 
injured  seed  will  float,  and  may  be  picked  out  or  poured 
off  and  destroyed.  Sound  seed  only  should  Ije  reserved  for 
planting. 

The  Cowpea  Weevil  (Bnichits  chincnsis  Linn.). — Cowpeas 
are  quite  liable  to  be  infested  by  the  cowpea  weevil  and  the 
four-spotted  bean  weevil,  which  injure  its  seed  in  the  same 
manner  as  the  common  bean  weevil.  Like  that  species  they 
begin  work  in  the  field  and  continue  to  breed  in  the  stored  seed, 


INSECTS    INJURIOUS    TO    BEANS   AND    PEAS  IO5 

until  they  entirely  spoil  it,  or  seriously  impair  its  germinating 
power.  Both  species  are  generally  distributed  and  injurious 
in  the  South,  and  are  widening  their  range  with  the  increasing 
use  of  their  food  plant  as  a  soil  renovator  and  as  forage.  They 
resemble  each  other  after  a  manner  superficially,  in  appearance 
as  in  habit,  but  they  differ  to  some  ex- 
tent in  various  details  of  their  life  econ- 
omy as  well  as  in  structure. 

The  cowpea  weevil  may  be  readily  dis- 
tinguished from  the  kindred  four-spotted 
species  by  the  two  large,  elevated  ivory- 
like lobes  at  the  base  of  the  thorax  and 
by  the  strongly  pectinate  antennae  of  the 
male    (fig.  61).     This   is   undoubtedly   an 

Old  World  species  and  an  ancient  enemy      ^'f-  ^•:-^.°™  ;^7.^"- 
^  ■'  (Author  s   illustration. 

of  edible  pulse.  u.  S.  Dept.  Agr.) 

Cowpea  is  the  favorite  food  seed,  but 
the  insect  is  also  injurious  to  common  and  pigeon  peas,  lentils, 
chick-pea  and  "mungo."  Table  beans  also  serve  as  food.  Mate- 
rial infested  by  this  weevil  undergoes  a  marked  elevation  in 
temperature.  In  one  instance  the  temperature  of  a  small  sack 
of  seed  infested  by  the  cowpea  weevil  was  found  to  be  25°  F. 
higher  than  the   surrounding   atmosphere. 

Remedies. — The  similarity  of  the  habits  of  this  and  the  com- 
mon bean  weevil  renders  it  amenable  to  the  same  remedies. 

The  Four-spotted  Bean  Weevil  {Bruchns  qiiadrimaculafus 
Fab.)  is  the  more  slender  species  and  differs  from  the  cowpea 
weevil  by  many  characters.  What  appears  to  be  the  commonest 
form  of  coloration  is  illustrated  in  figure  62,  a,,  which  is  suffi- 
cient to  separate  it  from  the  preceding  which  it  much  resembles, 
especially  in  its  manner  of  life. 

The  Remedies  are  practically  the  same  as  for  the  common 
bean  weevil. 


I06  INSECTS    INJURIOUS    TO    VEGETABLES 

The  Seed-corn  Maggot  (Pcgomya  fiisciccps  Zett.).— When 
the  seeds  of  beans,  peas,  corn  and  other  plants  fail  to 
develop,  damage  is  frequently  due  to  a  maggot  which  works 
by  scraping  the  seeds,  sprouts,  roots,  stalks,  and  stems  of 
plants  underground.'  Where  this  insect  works  decay  soon  sets 
in  and  the  plants  die.  Entire  plantings  are  sometimes  destroyed, 
but  when  only  a  few  seeds  or  sprouting  plants  are  attacked, 


Fig.  62.— Four-spotted  bean  v,-e3v:i.    a.  EeeJe:  b.  larva;  c,  pupa 
All  enlarged.    (Author's  illustration,  U  3.  Dept.  Agr.) 

injury  may  escape  notice.  Early  crops  suffer  most  and  if  they 
can  be  preserved  until  larger  growth  they  will  as  a  rule  sustain 
considerable  attack  without  material  damage. 

The  insect  in  question  is  called  the  seed-corn  maggot  and 
bean  fly,  and  its  parent  looks  like  a  small  house  fly.  It  can  be 
identified  by  the  male  (fig.  63,0)."  The  female  can  scarcely  be 
distinguished  from  related  species,  such  as  the  adults  of  the 
cabbage  root-maggot  and  onion  maggot.  The  length  is  about 
one-fifth  inch  and  the  wing  expanse  about  two-fifths.  The  larva 
is  footless  and  of  cylindrical  form  (d) ,  narrowed  at  the  anterior 
extremity  and  enlarged  posteriorly.     It  is  considerably  smaller 

1  Injury  of  this  character  is  also  committed  by  wireworms,  white  grubs  and 
some  other  insects,   e.  g.,  weevils  in  the  seeds. 

-  His  principal  characteristics  consist  of  a  row  of  short,  rigid,  bristly  hairs 
of  nearly  equal  length  on  the  inner  side  of  the  posterior  tibiae  or  shanks. 


INSECTS    INJURIOUS    TO    BEANS    AND    PEAS 


107 


than  the  onion  maggot,  measuring  about  one- fourth  of  an 
inch. 

This  fly  is  evidently  of  European  origin,  and  was  first  rec- 
ognized in  New  York  State  in  1856.  Like  so  many  other  flies, 
it  ranges  through  several  life  areas,  and  we  know  of  its  occur- 
rence in  New  England,  Canada  and  Minnesota,  southward  to 
the  Gulf,  and  westward  to  the  Pacific. 

Injury  is  most  severe  to  young  plants,  and  particularly  to 
beans,  peas,  and  Indian  corn.  Cabbage,  turnip,  radish,  beets, 
9  d 


Fig.  63.— Seed-corn  maggot  a.  Male  fly;  c,  head  of  female;  d,  larva,  from  side; 
e,  anal  segment  of  larva;  /,  anal  spiracles;  g,  thoracic  spiracles;  h,  puparium. 
All  much  enlarged.    (Author's  illustration,  U.  S.  Dept.  Agr.) 

onion,  seed  potato  and  hedge  mustard  are  also  attacked,  and  the 
maggots  even  feed  on  the  eggs  of  grasshoppers.  The  insect 
apparently  breeds  on  decaying  vegetable  and  perhaps  animal 
matter  of  various  kinds.  A  single  generation  only  develops  in 
corn,  but  later  ones  might  be  produced  on  bean  and  pea,  owing 
to  the  longer  period  in  which  these  crops  are  grown.  The  flies 
are  found  southward  throughout  the  year,  but  in  the  north  there 
must  be  a  period  in  midwinter  in  which  breeding  ceases;  per- 
haps also  another  in  midsummer. 


I08  INSECTS    INJURIOUS   TO   VEGETABLES 

METHODS    OF    CONTROL 

Owing  to  the  difficulty  of  destroying  root-maggots  and  the 
cost  of  the  chemicals,  growers  depend  largely  upon  methods  of 
prevention  which  should  be  employed  before  the  insect's  eggs 
are  laid. 

Sand  and  kerosene,  for  deterring  the  parent  flies  from  de- 
positing their  eggs,  consists  in  placing  sand  soaked  in  kerosene 
— a  cupful  to  a  bucket  of  dry  sand — at  the  base  of  the  plants, 
along  the  rows.  This  will  also  kill  young  maggots  that  might 
attempt  to  work  through  it. 

Mineral  fertilizers  are  useful  as  deterrents,  if  employed  just 
before  or  after  a  shower  has  thoroughly  wet  the  ground.  The 
principal  fertilizers  for  the  purpose  are  kainit,  nitrate  of  soda, 
and  chlorid  of  potash.  They  are  used  as  top  dressings  before 
planting ;  and  afterwards,  when  they  should  be  applied  as  nearly 
as  possible  to  the  roots,  the  earth  being  turned  away  from  the 
plants  for  this  purpose.  These  fertilizers  possess  the  advantage 
of  acting  also  as  a  stimulant  to  plant  growth,  thereby  facilitating 
recuperation  from  root-maggot  attack. 

Danger  from  organic  fertilizers. — Stable  manure  and  organic 
fertilizers  are  apt  to  induce  infestation,  since  this  species  devel- 
ops in  excrement  and  other  decomposing  material.  Numerous 
instances  of  this  have  come  to  the  writer's  knowledge.  It  is 
advisable,,  therefore,  to  avoid  the  use  of  manure,  rotted  leaves, 
or  other  organic  fertilizers,  and  to  avoid  planting  in  fields  in 
which  there  have  been  infested  or  diseased  plants. 

Hellebore  is  used  with  some  degree  of  success  in  Canada  as 
a  remedy  for  the  cabbage  and  onion  maggots. 

Carbolic  acid  emulsion  diluted  about  35  to  50  times,  is  partic- 
ularly applicable  when  this  species  occurs  in  radish  and  other 
plants  than  cabbage  and  cauliflower. 

Hand-picking,  although  laborious,  has  the  merit  of  effective- 
ness and  has  been  practiced  with  much  success  by  extensive 
growers.     It  consists  in  lifting  out  the  young  plants,  examining 


INSECTS    INJURIOUS    TO    BEANS   AND   PEAS 


109 


the  roots  for  the  maggots,  and  washing  them  in  a  strong  sohi-^ 
tion  of  soap,  after  which  they  are  replanted  and  in  two  or  three 
weeks  show  no  ill  effects  of  the  treatment.  By  careful  watching 
the  eggs  may  be  seen  about  the  stalks  of  the  young  cabbage 
plants,  and  if  the  soil  about  these  plants  be  raked  away  so  as 
to  expose  the  eggs  to  the  sun  they  will  dry  up,  thus  preventing 
the  maggots  from  hatching. 

Covering  young  plants  of  cabbage  and  cauliflower  in  seed- 
beds is  also  practiced  with  some  success  in  Canada. 

The  Bean  Ladybird  (Epilachna  corrupta  Muls.). — This  species 
is  limited  in  its  operation  as  regards  the  number  of  crop  plants 

r 


I  c 

Fig.  64.— Bean  ladybird,     a.  l_arva:  b,  beetle;  c,  pupa;  d,  egg  mass.    All  about  three 
times  natural  size.    (Author's  illustration,  U.  S.  Dept.  Agr.) 

affected  and  the  territory  invaded.  It  is  one  of  three  native 
ladybirds  that  live  by  choice  on  vegetables,  the  ©thers  being 
predaceous  and  subsisting  largely  on  plant-lice  and  soft-bodied 
larvae.  It  is  nearly  hemispherical,  and  its  length  is  a  little  more 
than  a  fourth  of  an  inch.  In  color  it  is  light  yellowish  brown, 
and  each  wing-cover  bears  four  black  spots   (fig.  64,6). 

Its  distribution  comprises  Colorado,  New  Mexico,  Arizona, 
western  Kansas,  and  Mexico. 

The  insect  is  described  as  being  the  worst  enemy  to  the  bean 
crop  in  the  West,  its  work  being  compared  to  that  of  the  Col- 
orado potato  beetle.  It  deVours  all  parts  of  a  bean  plant,  leaves, 
flowers,  and  green  pods.  The  female  deposits  her  yellowish- 
brown  eggs  in  large  clusters  (fig.  64,  d).  and  the  larvae  feed 
chiefly  on  the  lower  sides  of  the  leaves.     The  full-grown  larva 


no 


INSECTS    INJURIOUS   TO    VEGETABLES 


(a)  is  yellow  and  covered  with  stout  branched  spines.  Winter 
is  passed  in  the  adult  stage,  and  a  single  generation  has  been 
observed. 

Remedies. — Arsenate  of  lead  is  preferable  to  Paris  green  for 
use  on  beans  since,  unless  great  care  be  taken  in  the  application 
of  the  latter,  it  is  liable  to  scorch  the  leaves.  Kerosene  emul- 
sion has  given  good  results,  and  is  not  open  to  the  objection 


Fig.  65. -Bean  leaf-beetle,  a.  Adult  beetle;  b,  pupa;  c,  larva;  d,  side  view  of  anal 
segment  of  larva,  e.  leg  of  same;  /,  egg.  a,  b.  c.  Enlarged  about  six  times;  d,  e,  f, 
more  enlarged.    (Author's  illustration,  U.  S.  Dept.  Agr.) 


of  poisoning  the  plants  as  in  the  case  of  an  arsenical.  Hand- 
picking  the  beetles  and  eggs  on  their  earliest  appearance  is  a 
measure  of  prevention  that  would  compensate  for  the  time  and 
labor  in  kitchen  gardens. 

The  Bean  Leaf -beetle  (Ccrotoma  trifurcata  Forst.).— An  in- 
sect of  considerable  importance  in  the  Gulf  States,  and  in  some 
years  farther  north  is  the  bean  leaf-beetle.  It  has  attracted  at- 
tention by  its  injuries  in  New  Jersey.  Louisiana,  Indiana,  Dela- 
ware, Ohio,  Maryland,  and  Virginia.  Injury  is  due  to  the 
adult  beetle,  which  eats  large,  round  holes  in  growing  leaves  of 
bean  and  cowpea,  and  certain  other  leguminous  plants,  including 


[NSECTS    INJURIOUS   TO    BEANS   AND    PEAS 


III 


cultivated  beggarweed  or  tickseed.     The  larvae  feed  on  the  roots 
and  main  stems  of  the  same  plants  just  below  the  surface. 

The  beetle  resembles  in  several  particulars  the  cucumber 
beetles.  It  measures  from  a  seventh  to  a  fifth  of  an  inch  in 
length,  and  varies  in  color  from  pale  yellowish  or  buff  to  dull 
greasy  red,  with  black  markings,  arranged,  in  what  appears  to 
be  the  typical  form,  as  in  figure  65,  a.  Individuals  occur,  how- 
ever, in  which  the  elytral  marking  is  entirely  wanting. 

This  species  is  native  and  found  from  Canada  southward  to 
the  Gulf  States  and  westward  to  Kansas  and  Minnesota. 

In  the  South  the  beetles  appear  in  April,  and  northward  as 
late  as  June.  The  minute  orange-colored  eggs  (fig.  65,/)  are 
laid  about  the  stem  of  the  insects'  food  plant,  in  clusters  of  six 
or  more,  and  the  larvae  eat 
around  the   stem  and   roots. 

Remedies. — Hand-picking  and 
pyrethrum  are  useful  in  small 
gardens  early  in  the  season ;  but 
our  chief  reliance  is  in  arseni- 
cals  when  the  insect  is  numer- 
ous. Arsenate  of  lead  should 
be  employed  on  the  first  appear- 
ance of  the  beetles  in  order  to 
stop  them  at  the  outset.  An 
important  measure  is  the  care- 
ful weeding  out  of  wild  food 
plants,  such  as  tick  trefoil  and  bush-clover,  in  the  neighborhood 
of  cultivated  fields. 

The  Pea  Moth  (Srmasia  nigricana  Steph.). — In  Canada,  where 
pea-growing  is  an  important  industry,  there  is,  in  addition  to 
the  pea  weevil  discussed  in  previous  pages,  a  seed-infesting  in- 
sect known  as  the  pea  moth,  the  larva  of  which  develops  in 
ripening  peas  in  the.  pods.  The  moth  (fig.  66)  is  a  small 
Tortricid,  with  a  wing  expanse  of  about  half  an  inch.     The 


Fig.  66.— Pea  moth  'Steph  )  Moth  above, 
larva  below.  About  three  times  natural 
size.  (Author's  illustration,  U.  S.  Dept. 
Agr.) 


112 


INSECTS    INJURIOUS    TO    VEGETABLES 


larva  is  whitish-yellow  with  a  pale  brown  head  and  thoracic 
shield,  the  latter  inconspicuous.  This  is  a  comparatively  new 
importation  from  the  Old  World  and  it  is  as  yet  unknown  in  the 
United  States,  but  it  will  probably  in  time  invade  our  Northern 
States,  and  pea-growers  should  be  warned  against  it.  The 
remedy  which  gives  best  results  is  early  planting  of  the  earliest 
ripening  varieties. 

The  Bean  Leaf-roller  {Eudamus  protcus  Linn.). — This  species 
is  injurious  in  the  Gulf  States  to  beans,  cowpea  and  cultivated 


Fig.  67.— Bean  leaf-roller,    a,  Butterfly;  6,  larva,  dorsal  view;  c,  larva,  lateral  view;  d, 
pupa  in  roUed-up  leaf.    Somewhat  enlarged.    (Author's  illustration,  U.  S.  Dept.  Agr.) 


"beggarweed."  It  is  the  caterpillar  of  a  butterfly  called  the 
swallow-tailed  skipper.  The  ground  color  of  the  caterpillar  is 
yellowish,  its  head  being  darker  and  marked  with  two  orange 
spots  near  the  mandibles.  The  head  is  prominent  and  separated 
from  the  body  by  the  narrow  neck,  a  character  which  will  dis- 
tinguish it  from  any  other  common  caterpillar  on  garden  crops 
(fig.  67). 


INSECTS    INJURIOUS   TO    BEANS    AND   PEAS 


113 


Cutworms  and  Other  Caterpillars. — Xumerous  other  caterpil- 
lars devour  the  foliage  of  beans  and  peas  of  which  cutworms 
are  among  the  most  important,  often  causing  extensive  damage 
to  young  plants  by  cutting  them  ofif  near  the  ground,  and  to 
older  plants  by  severing  their  leaves  and  tender  shoots.  Cut- 
worm remedies  are  considered  on  page  54. 

A  green-striped  caterpillar  (fig.  68),  misnamed  the  bean  cut- 
worm  (Ogdocoiita  cincrcola  Guen.),  does  injury  to  the  foliage 


Fig.  68.— Bean  cutworm    Ogdoconta  cinereolai.    a.  Moth,  b.  larva;  c,  abdominal  seg- 
ments nf  larva;  d,  pupa.    All  enlarged.    (Author's  illustration,  U.  S.  Dept.  Agr.) 

and  pods  of  beans,  sometimes  stripping  the  vines  bare.  Other 
troublesome  species  include  the  zebra  caterpillars,  the  yellow 
bear  and  salt-marsh  caterpillars. 

The  bollworm  or  corn-ear  worm  (Heliothis  obsolcta  Fab.)  is 
a  very  serious  enemy  of  beans  frequently  destroying  the  seed  by 
crawling  into  the  green  pods.  No  means  of  preventing  this 
form  of  injury  is  known.  A  more  extended  account  of  this 
pest  will  be  given  under  "Insects  Injurious  to  Sweet  Corn." 

The  caterpillar  of  a  beautiful  little  butterfly,  the  gray  hair- 
streak  (Thecla  melinus  Hbn.)  is  sometimes  injurious  to  beans 
and  peas  by  eating  into  the  pods.  The  butterfly  is  on  the  wing 
almost  continuously  from  May  to  September  in  the  North,  and 
from  March  to  November  farther  South.     This  species  seldom 


114 


INSECTS    INJURIOUS    TO    VEGETABLES 


does  severe  damage,  hence  little  precaution  need  be  observed  m 
the  treatment  of  it,   further  than  to  destroy  all  affected  pods, 


Fig.  69.— Gray  hair-streak,    a.  b.  Butterfly;  c.  larva,  d.  pupa;  e.  egg.  much  en- 
larged; others  somewhat  enlarged-    (Howard  &  Chittenden,  U.  S.  Dept.  Agr.) 

that  the  insect  may  not  develop  and  do  injury  later  and  in  after 
years  (fig.  69). 

It  may  be  successfully  controlled  by  a  spraying  with  an  ar- 
senical on  its  first  appearance. 

The  Pea  Aphis  {Nectarophora  destructor  Johns.). — Until  the 
year  1899  peas  grown  in  the  United  States  suffered  little  injury 
from  insects  other  than  the  pea  weevil.  In  that  and  the  fol- 
lowing year,  however,  this  crop  was  badly  injured  by  the  pea 
aphis,  which  caused  enormous  losses  in  our  principal  pea- 
growing  regions,  especially  where  peas  are  grown  for  canning. 
It  was,  in  fact,  one  of  the  most  destructive  of  all  insects  that 
ravaged  crops  in  the  United  States  at  that  time. 

This  aphis  is  of  unusual  size  among  those  found  in  gardens, 
and  the  largest  green  species  which  attack  the  pea  and  related 
plants.  The  length  of  the  body  of  winged  viviparous  females 
is  about  3/16  inch,  and  the  total  wing  expanse  about  4/10  inch. 
The  general  color  of  both  the  winged  and  apterous  or  wingless 
forms  is  uniform  pea-green,  the  same  as  its  food  plants.  As 
to  whether  this  insect  is  native  or  of  foreign  origin  there  is 
still  some  doubt. 


INSECTS    INJURIOUS   TO    BEANS    AND    PEAS 


115 


During  the  years  mentioned  this  pea  aphis  overran  and  laid 
waste  fields  of  peas  from  Nova  Scotia  to  Virginia  and  Mary- 
land, in  the  last  as  well  as  neighboring  States,  destroying  about 
50  per  cent,  of  the  annual  output,  and  this  in  spite  of  vigorous 
efforts  that  were  made  to  control  it.  An  estimate  of  the  loss 
for  1899  along  the  Atlantic  Coast  States  reached  the  sum  of 


czn::jC7 


Fig.  70.— Pea  aphis,  a.  Winged  female;  b,  same  from  side  with  wings  folded  in  natural 
position  when  feeding;  c,  apterous  female;  d,  nymph  in  last  stage;  e.  third  joint  of 
antenna  of  winged  form,  a-d.  Much  enlarged,  e.  more  highly  magnified.  (Author's 
illustration,  U.  S.  Dept.  Agr.) 

$3,000,000.  During  1900  the  loss  over  the  same  area  was  placed 
as  early  as  June  15  at  $4,000,000.  Several  cases  of  severe 
damage  were  reported,  in  which  80  or  more  per  cent,  of  the  peas 
on  farms  of  500  or  600  acres  were  completely  destroyed.  In 
short,  pea-growers  as  far  westward  as  Wisconsin  sustained  such 
severe  losses  as  to  give  rise  to  the  expression  that  the  country 
had  been  visited  by  a  veritable  scourge. 

Attack  begins  on  the  young  vines ;  the  "lice"  gather  in  clusters 
about  the  terminals,  and  as  the  leaves  become  covered  they 
attack  the  stems,  and  by  their  numbers  and  voracity  sap  the 
life  of  the  plant.    Whole  areas  are  frequently  seen  covered  with 


Il6  INSECTS    INJURIOUS    TO    VEGETABLES 

the  "lice,"  which  in  a  very  few  weeks  destroy  a  crop.  Attack 
is  seldom  noticed  until  May  in  the  more  Southern  States  in 
which  the  insect  is  found,  and  a  little  later  in  its  more  northern 
range.  It  hibernates  on  clover  and  vetch,  and  from  these  plants 
spreads  by  flight  in  April  and  May  to  peas.  The  females  at 
certain  periods  produce  living  young.  These  attain  maturity  in 
from  ten  to  fifteen  days,  and  possibly  in  less  time  in  the  hottest 
weather.  Several  generations  develop  each  year.  As  instance 
of  the  reproductive  powers  of  this  insect.  Prof.  W.  G.  Johnson's 
estimate  is  interesting.  Females  produce  from  no  to  120  young. 
Calculating  from  the  average  number  of  insects  produced  each 
day  (six),  one  individual  would  in  one  year  become  the  pro- 
genitor of  423,912  "lice." 

In  some  instances  natural  enemies  of  the  pea  aphis  have  done 
efficient  service.  Seldom,  however,  do  they  destroy  the  insects 
sufficiently  early  in  the  season  to  save  a  crop. 


Kerosene-soap  emulsion,  carefully  prepared  and  diluted  with 
about  twelve  parts  of  water,  and  sprayed  upon  the  plants  upon 
the  first  appearance  of  the  "lice,"  so  that  the  leaves  are  wet  on 
both  the  under  and  upper  surfaces,  has  been  found  to  be  the 
most  effective  of  the  insecticides  tried.  A  stronger  solution  is 
apt  to  scald  the  plant,  particularly  while  the  vines  are  young 
and  tender.  The  cost  of  the  emulsion,  however,  and  the  diffi- 
culty of  under-spraying,  its  rapid  evaporation,  and  the  necessity 
of  frequent  applications,  is  such  as  to  hardly  warrant  its  use. 

Brush  and  cultivator  method. — The  peas  are  grown  in  rows 
sufficiently  wide  apart  as  to  admit  of  a  one-horse  cultivator  be- 
tween them.  The  "lice"  are  brushed  from  the  plants  with 
boughs  of  pine  with  their  leaves  on,  and  a  cultivator  follows 
down  the  rows  immediately  afterward.  This  method  should  be 
practiced  in  the  heat  of  the  day,  when  the  ground  is  dry  and 
hot,  and  a  repetition  o^  the  brushing  is  necessary  every  three 


INSECTS    INJURIOUS   TO   BEANS   AND   PEAS 


117 


to  seven  days  until  the  crop  is  ready  for  picking.  Such  "lice" 
as  are  not  buried  in  the  ground  will  be  killed  by  the  dust  which 
closes  their  breathing  pores,  while  a  considerable  proportion 
are  destroyed  also  by  the  force  of  the  brushing.  Peas  planted 
in  rows  to  permit  of  frequent  cultivation  suffer  much  less  injury 
than  when  sown  broadcast.  As  soon  as  the  last  picking  has 
been  made  infested  plants  should  be  promptly  plowed  under. 

Cultural  methods. — Of  cultural  methods  there  is  testimony  to 
the  value  of  early  planting,  the  earliest  peas  seldom  being  in- 
fested, or  at  least  only  slightly  injured.  Very  late  plantings 
of  peas  for  canning  have  also  escaped  ravages  in  some  instances. 

Rotation  of  crops  is  advisable,  and  it  is  unwise  to  plant  peas 
in  successive  years  in  the  same  portion  of  a  farm,  or  in  the 
vicinity  of  other  leguminous  plants  likely 
to  harbor  this  species. 

As  this  insect  passes  the  winter  on 
the  plants  mentioned,  because  peas  are 
not  available,  it  might  be  possible  to 
use  small  plats  of  some  of  them  as  trap 
crops.  Crimson  clover  would  probably 
be  best  because  of  the  early  start  that 
it  gets  in  the  spring.  On  the  trap  plants 
the  "lice"  could  be  killed  by  hand 
methods,  such  as  brushing  from  the 
plants  into  pans,  and  thus  large  numbers    ^'S-    -i-   c.any  leafnopper. 

Adult.  (Author's  illustration, 

could  be  killed  early  in  the  season  be-      u.  s.  Dept.  Agr.) 
fore  they  had  opportunity  to  spread  to  peas. 

Leafhoppers  of  several  species  occur  in  all  stages,  feeding 
on  the  under  surface  of  leaves  of  bean  and  cowpea,  but  are  not 
known  to  be  particularly  injurious.  The  most  conspicuous 
species,  on  account  of  its  large  size  and  bright  colors,  is  the 
crafty  leafhopper  (Diedroccphala  versiita  Say,  fig.  71).  Rem- 
edies have  been  discussed  on  page  86. 

Plant-bugs  are  often  abundant  on  edible  legumes.     Of  these 


Il8  INSECTS    INJURIOUS    TO   VEGETABLES 

the  garden  flea-hopper  (Halticus  uhleri  Giard)  lives  in  great 
numbers  on  the  leaves,  puncturing  them  so  as  to  cause  tht  death 
of  the  tissues  in  small  irregular  white  patches.  In  its  snort- 
winged  form  (fig.  y2,  a)  it  resembles  the  black  flea-beetles,  which 
affect  potato,  alike   in   appearance,   in  the   nature  of  its   work, 


Fig.  72.— Garden  flea-hopper,    a,  Brachypterous  female;  fc.  full-winged  female      All 
much  enlarged.    (Authors  illustration  U.  S  Dept.  Agr.) 

and  in  its  saltatory  power.  Other  food  plants  include  potato, 
pumpkin,  cabbage,  ornamental  plants,  clover  and  many  weeds. 
Remedies  are  the  same  as  for  leafhoppers.  Beans,  peas  and 
other  plants  subject  to  injury  should  not  be  planted  in  or  near 
old  clover  fields. 

Nuttall's  Blister  Beetle  (Contharis  nuttalli  Say). — Blister 
beetles  do  much  injury  to  leguminous  food  crops  and  are  par- 
ticularly harmful  to  beans  and  peas.  Nuttall's  blister  beetle  is  a 
large  and  beautiful  insect,  variable  both  in  color  and  size  (fig. 
73).  It  is  bright  metallic  green,  the  head  and  thorax  have 
usually  a  coppery  luster,  and  the  wing-covers  are  often  purple. 
It  varies  from  a  little  over  half  to  nearly  an  inch.  Its  habitat 
extends  from  the  northern  Mississippi  valley  region  to  the 
Rocky  Mountains,  and  it  is  abundant  from  South  Dakota  to 
the  northwest  territories  of  Canada.  It  is  related  to  the  Spanish 
fly.  the  Cantharis  vesicatoria  or  cantharides  of  commerce,  has 


INSECTS    INJURIOUS   TO   BEANS   AND    PEAS  1 19 

the  same  blistering  properties,  and  might  be  put  to  the  same  use. 
The  beetles  make  their  first  appearance  about  the  first  of  July, 
ravenously  devour  the  blossoms  and  tender  leaves  of  beans  and 
other  vegetables,  and,  if  report  speaks  truly,  they  are  capable 
of  destroying  a  crop  in  a  day. 

From  the  rapidity  with  which  this  insect  works,  poisons  are 
of  little  value.  We  must,  therefore,  resort  to  mechanical  meas- 
ures, and  in  their  employment  promptness  and  thoroughness  are 


Fig.    74.— Ash-gray   blister  beetle. 
Fig.  73.— Nuttalls  blister  beetle.  Female  at  right,  twice  natural  size; 

One-third  larger  than  natural  male  antenna  at  left.    Greatly  en- 

size.      (Author  s    illustration,  larged.    (Author's  illustration,  U.  S. 

U.  S.  Dept.  Agr.)  Dept.  Agr.) 

essential.  The  beetles  may  be  destroyed  by  driving  them  into 
windrows  of  dry  straw  or  similar  material  and  burning  them; 
by  sweeping  them  into  a  net,  such  as  is  used  by  insect  collectors, 
and  throwing  the  captured  insects  into  a  fire ;  or  by  beating 
them  into  specially  prepared  pans  of  water  on  which  there  is 
a  thin  scum  of  coal  oil. 

The  Ash-gray  Blister  Beetle  (Macrobasis  unicolor  Kby.).— 
This  is  one  of  our  commonest  Eastern  species  (fig.  74),  and 
although  very  destructive  to  beans  and  peas,  is  also  a  serious 
enemy  of  beets,  potato,  and  tomato,  and  attacks  besides  sweet 
potato  and  some  flowering  plants. 

Blister  beetle  remedies  are  discussed  on  page  68. 


CHAPTER   VIII 


INSECTS  INJURIOUS  TO  BEETS  AND  SPINACH 

The  recent  extension  of  the  sugar-beet  industry  in  this 
country  has  been  the  means  of  bringing  to  notice  a  large  number 
of  insects  not  previously  identified  with  that  plant.  Owing  to 
its  lesser  prominence  as  a  merchantable  product,  spinach  is  not 
grown  to  the  same  extent,  and  it  follows  that  its  known  insect 
enemies  are  fewer  still.  With  the  exception  of  some  insects 
which  will  be  mentioned,  the  majority  of  those  which  live  more 
or  less  habitually  on  beets  and  spinach  feed  normally  on  related 
wild  plants,  including  the  goosefoot,  amaranth,  saltbush  and 
the  like.  During  the  last  quarter  century  several  insects  have 
been  so  prominent  as  pests  in  fields  of  sugar-beet,  that  they 
have  received  names  indicative  of  their  beet-feeding  habit,  while 
some  few  take  their  common  names  from  spinach.  Of  these 
are  the  beet  army  worm,  beet  webworm,  spinach  leaf-miner, 
spinach  flea-beetle,  beet  carrion-beetle  and  the  beet  aphis.  Up 
to  1907  nearly  200  species  of  insects  have  been  observed  to  use 
beets  as  food. 

The  greatest  losses  from  insect  attack  are  probably  due  to 
flea-beetles,  but  they,  as  well  as  cutworms  and  similar  groups, 
are  so  irregular  in  their  depredations  that  an  exact  estimate 
cannot  be  made.  Different  species  of  leaf-beetles  and  cater- 
pillars, other  than  cutworms,  do  more  or  less  injury,  and  several 
blister  beetles  devour  the  foliage  of  sugar  and  table  beets  freely ; 
most  forms  of  the  last,  however,  usually  make  their  appearance 
so  late  in  the  season  that,  although  defoliation  may  be  excessive, 
comparatively  little  damage  is  accomplished.  The  same  is  true 
of  some  species  of  grasshoppers.    Two  common  forms  of  farm 

120 


INSECTS    INJURIOUS   TO    BEETS    AND    SPINACH  121 

insects,  white  grubs  and  wirewornis,  are  at  times  injurious  to 
the  roots,  and  root-aphides  injure  the  roots  so  as  to  render 
them  comparatively  useless. 

FLEA-BEETLES  AND  LEAF-BEETLES 

As  flea-beetles  are  among  the  most  troublesome   sugar-beet 
pests  from  their  early  occurrence  and  the  rapidity  with  which 


bb  b 

Fig.  75.— Spinach  flea-beetle,  a.  Beetle;  b,  egg  mass,  showing  mode  of  escape  of  larva 
at  right:  66,  sculpture  of  egg;  c,  full-grown  larva;  d.  pupa;  e,  newly-hatched  larva;/, 
abdominal  segment  of  same,  a,  c,  d.  Five  times  natural  size;  6..  e,  more  enlarged;  bb,  f, 
still  more  enlarged.    (Author's  illustration,  U.S.  Dept.  Agr.) 

they  work,  they  may  receive  first  mention,  especially  as  no  less 
than  twenty  forms  have  been  observed  attacking  this  plant 
Some  of  these  are  widely  distributed;  others  are  local.  Most 
farmers  are  familiar  with  flea-beetles,  better  known  perhaps  as 
"fleas,"  and  it  will  be  unnecessary  to  enter  into  detail  in  regard 
to  more  than  one  species. 

The  Spinach  Flea-beetle  (Disonycha  xanthomclcena  Dalm.). — 
This  flea-beetle  (fig.  75)  is  black  with  a  reddish-yellow  thorax. 
It   appears   early    and,    like    other    species   of    its    kind,    works 


122  INSECTS    INJURIOUS   TO   VEGETABLES 

rapidly.  It  can  be  controlled  in  the  same  manner  as  other  flea- 
beetles  and  leaf -beetles,  and  there  is  no  doubt  that  if  growers 
took  pains  not  to  allow  chickweed  and  lambsquarters  to  spring 
up  in  the  fields  that  the  insect  could  be  still  more  easily  de- 
stroyed, as  the  first  generation  is  produced  on  this  and  some 
similar  weeds,  and  it  is  the  second  generation  which  attacks 
the  beets.  Its  young,  or  larva,  has  the  same  habit  as  the  adult, 
and  the  species  frequently  "cleans  out"  entire  rows  of  beets 
before  its  appearance  is  suspected. 

Remedies  for  flea-beetles  are  discussed  on  page  65. 

The  Larger  Beet  Leaf -beetle  (Monoxia  piincticollis  Say). — 
Two  species  of  native  leaf-beetles  are  important  enemies  of  the 
sugar-beet  in  the  West,  where  they  are  sometimes  known  as 
"French  bugs"  and  "alkali  bugs." 

The  larger  beet  leaf-beetle  (fig.  76)  lays  her  eggs  on  the 
under  side  of  leaves,  where  they  hatch  in  about  six  days,  the 
young  larvae  commence  feeding  at  once,  continuing  for  nine  or 


Fig.  76 —Larger  beet  leaf-beetle  a.  Female  beetle;  b  eggs:  c,  larva,  o  ,  male  claw: 
?  .  female  claw.  All  much  enlarged,  claws  more  enlarged.  (Author  s  illustration. 
U.S.  Dept.  Agr.) 


ten  days,  when  they  dig  their  way  into  the  ground,  and,  a  few 
days  later,  come  forth  as  beetles.  Damage  is  due  to  both  the 
larvae  and  beetles,  hundreds  occurring  on  a  single  plant,  which 


INSECTS    INJURIOUS    TO    BEETS    AND    SPINACH  I23 

ir,  either  consumed  or  so  injured  that  it  shrivels  and  dies.  Since 
1897  this  species  has  done  more  or  less  injury  to  sugar-beet  in 
Colorado,  Idaho,  Utah  and  neighboring  States,  the  beetles  often 
occurring  in  swarms  like  blister  beetles.  This  species  resembles 
the  elm  leaf-beetle,  but  is  larger  and  differently  marked.  It  is 
oblong,  narrow  in  front  and  dull  brown  while  the  wing-covers 
are  more  or  less  distinctly  striped. 

The  Western  Beet  Beetle   (Monoxia  consputa  Lee). — Beets 
are  much  injured  by  this  species  along  the  Pacific   Coast.     It 


Fig     77.— Western    beet     beetle. 

Eight  times  natural  size;  antenna  Fig.    78— Margined     blister 

at  left  highly  magnified.  (Author's  beetle.     Enlarged.     (Author's 

illustration.  U.  S.  Dept.  Agr.)  illustration.  U.  S-  Dept.  Agr.) 

eats  holes  through  the  leaves,  in  some  instances  leaving  only 
a  network  of  the  original  leaf,  and  this  seriously  interferes  with 
the  growth  of  young  plants,  which  are  s  )metimes  killed.  This 
beetle  (fig.  yy)  is  closely  related  to  the  preceding,  but  is  smaller, 
measuring  only  about  one-sixth  of  an  inch  in  length. 

Remedies. — These  beet  leaf-beetles  are  important  enemies  of 
sugar-beet  culture.  The  general  methods  for  the  control  of  leaf 
and  flea-beetles  (see  page  65)  are  applicable,  but  a  few  re.narks 
should  be  added  in  regard  to  particular  remedies.  Paris  green, 
London  purple,  and  paragrene  have  all  been  employed  against 
the   larger   species   with   apparently  good   results   when   applied 


124  INSECTS    INJURIOUS   TO   VEGETABLES 

dry,  mixed  with  flour,  in  the  same  manner  as  for  the  Colorado 
potato  beetle.  The  beetles  accumulate  quite  largely  upon 
"mother"  beets  early  in  spring,  which  suggests  that  if  a  few 
beets  be  left  in  the  ground  over  winter  they  will  serve  as  trap 
crops  for  the  protection  of  the  younger  plants  in  spring.  The 
larger  species  practically  confines  its  injuries  to  plants  growing 
in  or  in  close  proximity  to  alkali  soil.  Hence  such  ground  is 
to  be  avoided  for  the  cultivation  of  beets. 

BLISTER    BEETLES 

Blister  beetles  are  among  the  most  conspicuous  of  all  beet 
enemies,  and  no  less  than  1 1  species  have  been  observed  as 
doing  injury  to  sugar-beet  alone.  One  of  the  commonest  is  the 
margined  blister  beetle  (Epicaiita  marginata,  fig.  78).  The 
writer  has  seen  entire  plantings  of  beet  almost  completely  de- 
foliated by  it;  but  as  a  rule  this  and  several  of  the  other  beet- 
feeding  blister  beetles  occur  too  late  in  the  season  to  do  material 
harm,  as  the  roots  have  by  this  time  made  nearly  complete 
growth.  This  species  also  attacks  beans,  potatoes  and  tomatoes, 
as  well  as  other  vegetables,  and  is  destructive  to  some  flowering 
plants.     It  is  most  abundant  in  July  and  August. 

Remedies  are  the  same  as  for  other  blister  beetles  (page  68). 

CUTWORMS    AND    OTHER    CATERPILLARS 

When  sugar-beets  are  cultivated  over  a  large  territory,  there 
is  comparatively  little  danger  of  injury  from  common  cutworms 
which  are  such  serious  pests  in  the  vegetable  garden.  Certain 
species,  however,  occur  occasionally  in  great  numbers,  spreading 
from  field  to  field,  like  the  army  worms,  and  sometimes 
sweep  everything  before  them,  as  they  feed  upon  every  portion 
of  the  plant— foliage,  flowers,  stalks,  and  even  roots.  At  such 
times  they  should  be  promptly  destroyed.  Methods  of  control 
employed  against  cutworms  are  considered  on  page  54.  When 
traveling  in  armies  cutworms  should  be  treated  as  army  worms 
(see  p.  58). 


INSECTS    INJURIOUS    TO    BEETS    AND   SPINACH 


I-'5 


The  Beet  Army  Worm  {Laphygma  cxigua  Hbn.).— .This 
species  has  come  into  prominence  since  the  extensive  cultivation 
of  the  sugar-beet  in  the  West.  It  is  rapidly  widening  in  distribu- 
tion, chiefly  by  the  flight  of  the  mature  insect,  a  moth  resembling 
the  parents  of  the  cutworms.  This  insect  might  be  a  still  more 
injurious  sugar-beet  pest  than  is  yet  known,  save  for  the  fact 
that  it  attacks  many  other  crops  and  weeds. 

The  moth  (fig.  79,  a)  is  of  a  gray  color,  resembling  the  plain 
form  of  the  fall  army  worm,  to  which  species  it  is  related.    The 


Fig.  79.— Beet  army  worm,  a,  Moth;  b,  larva,  lateral  view;  c.  larva,  dorsal  view:  a.  head 
of  larva;  e.  egg.  viewed  from  above;  f,  egg,  from  side-  All  enlarged.  (Author  s  illus- 
tration, U.  S.  Dept.  Agr.) 

fore-wings  are  broader  and  paler,  and  the  reniform  and  other 
spots  as  well  as  mottlings  are  more  distinct.  The  wing  expanse 
is  less  than  an  inch  and  one-half.  The  larva  is  striped,  as 
shown  at  b  and  c. 

Remedies. — When  occurring  in  numbers  this  insect  can  be 
controlled  by  means  of  an  arsenical,  but  when  unduly  abundant, 
army  worm  remedies  are  necessary. 

The  Beet  Webworm  (Loxostcgc  sticticalis  Linn.).— This  in- 
sect is,  like  the  preceding,  of  foreign  origin,  and  is  also  rapidly 


126 


INSECTS    INJURIOUS    TO   VEGETABLES 


increasing  its  range,  and  as  it  has  developed  an  unusual  fond- 
ness for  sugar-beet  it  will  in  time  become  a  beet  pest  of  great" 
importance.  It  has  evidently  been  introduced  on  the  Pacific 
Coast  and  has  been  found  destructive  as  far  eastward  as 
Michigan  and  Nebraska,  and  has  done  considerable  injury  in 
other  localities,  including  Canada  where  it  was  recently  very 
destructive.  It  is  cousin  to  the  native  garden  webworm,  which 
it  resembles  in  general  form.     It  is,  however,  darker  and  about 


Fig.  80.— Beet  webwo.m.  a.  Moth,  twice  natural  size;  b,  larva,  less  enlarged;  e.  upper 
surface  of  first  proleg  segment  of  larva;  d.  side  view  of  same;  c,  d.  more  enlarged- 
(After  Insect  Life.) 

one-fourth  larger.  Fully  expanded  the  wings  measure  nearly 
an  inch,  and  are  purplish  brown  in  color,  with  darker  and  paler 
bands,  as  shown  (fig.  80,0).  The  hibernating  caterpillars  make 
a  burrow  beneath  the  surface  of  the  ground  and  construct  a 
cocoon  about  three  times  as  long  as  themselves.  A  similar  but 
shorter  cocoon  is  made  by  the  midsummer  brood. 

A  favorite  wild  food  plant  of  this  species  has  been  observed 
— the  pigweed  or  careless  weed  (Amaranthus) — and  injury  to 
sugar-beet  has  been  observed  in  many  cases  where  the  ground 
was  allowed  to  run  to  the  wild  plant. 

Remedies. — The  destruction  of  this  and  other  weeds  might 
in  time  lead  to  comparative  immunity  from  the  attack  of  the 
webworm.  Paris  green  or  other  arsenical  sprayed  several  times 
over  the  infested  plants  will  also  compass  its  destruction. 


INSECTS    INJURIOUS    TO    BEETS    AND    SPINACH 


127 


Other  kinds  of  caterpillars,  including  such  well-known  forms 
as  the  zebra  and  salt-marsh  caterpillars,  are  often  found  in  beet 
fields,  but  seldom  in  sufficient  numbers  to  do  serious  injury.  As 
a  rule  they  readily  yield  to  sprays  of  Paris  green. 

GRASSHOPPERS 

Grasshoppers,  or  locusts,  as  well  as  crickets  and  some  related 
insects,  are  of  great  importance  in  the  West,  and  frequently  do 
injury  to  sugar-beets.     Many  species  attack  this  plant. 

Remedies. — The  hopper-dozer  is  a  necessary  implement  in  our 
warfare  against  this  class  of  pests.  It  is  discussed  with  other 
grasshopper  remedies  on  page  71. 


Fig.  81  —Beet  leaf-miner,  a.  Fly;  b.  head  of  male  fly:  c.  head  of  female;  d.  surface 
of  egg,  highly  magnified;  e,  egg,'  /,  maggot;  g,  head  of  same;  /,  anal  segment;  k.  ana! 
spiracles.    All  enlarged.    (After  Howard,  U  S-  Dept.  Agr.) 

LEAF-MINERS 

Hitherto  insects  which  affect  chiefly  the  foliage  by  chewing 
have  been  treated.    We  now  come  to  a  consideration  of  insects 


128  INSECTS    INJURIOUS    TO    VEGETABLES 

of  different  habits,  and  among  these  are  the  leaf-miners — small, 
white  maggots  producing  two-winged  flies  resembling  the  house 
fly.  These  burrow  between  the  two  surfaces  of  the  leaves  and 
form  blotches  termed  mines.  The  principal  species,  the  beet 
or  spinach  leaf-miner  (Pcgomya  vidua  Lint.),  is  illustrated 
(fig.  8i).  We  have  not  as  yet  ascertained  any  perfectly  satis- 
factory remedy  for  the  leaf-miners. 

PLANT-BUGS,    LEAFHOPPERS   AND   APHIDES 

Hordes  of  sucking  insects,  many  plant-bugs,  leafhoppers 
and  numerous  related  forms  are  present  in  fields  of  sugar-beet 
at  all  times,  and  sometimes  accomplish  very  considerable  in- 
jury. Among  the  most  prominent  of  these  are  the  false  chinch- 
bugs. 

The  most  satisfactory  manner  of  keeping  false  chinch-bugs 
in  check  is  by  clean  farming  methods,  destroying  purslane  and 
other  weeds,  and  the  cleaning  up  of  crop  remnants  before 
winter,  so  as  to  leave  no  place  for  the  insects  to  pass  the 
winter.  Some  growers  have  observed  that  the  flooding  of 
fields  infested  by  these  insects  forces  them  to  leave,  and  the 
growing  of  mustard  as  a  trap  crop  gives  good  results,  provided 
the  precaution  is  always  taken  to  destroy  the  mustard  before  it 
runs  to  seed. 

The  sugar-beet  leafhopper  (Eittcttix  tcnclla  Baker)  came  into 
prominence  as  a  beet  pest  in  Utah,  Idaho  and  Colorado  in  1905, 
doing  damage  that  year  estimated  at  $500,000.  This  insect  has 
become  locally  known  as  "white  fly"  and  its  injury  as  "blight." 
It  has  been  noticed  that  late-planted  beets  are  principally 
damaged  and  that  early  plants  are  less  injured,  and  it  may  be 
that  on  this  or  a  similar  point  in  its  life  economy  may  hinge 
the  remedy.  It  is  worthy  of  remark  that  the  species  was  un- 
known to  science  until  1900. 

For  the  aphides  which  attack  sugar-beet,  it  is  sometimes  un- 


INSECTS    INJURIOUS   TO    BEETS   AND   SPINACH  I29 

necessary  to  employ  remedies,  as  these  creatures  are  peculiarly 
susceptible  to  atmospheric  conditions,  doing  their  greatest  in- 
jury in  cool,  damp  weather,  and  being  held  in  nearly  complete 
abeyance  at  times  by  numerous  natural  enemies  which  flourish 
in  dry  and  even  hot  weather,  as  is  very  well  known.  In 
gardens  of  table  beets,  kerosene  emulsion,  pyrethrum  and  fu- 
migation, according  to  directions  given  on  page  165,  are  of  value. 
Practically  none  of  these  remedies  can  be  employed  on  large 
fields,  but  are  useful  in  small  ones.  Clean  farming  and  fall 
plowing  are  always  advisable,  and  crop  rotation  should  be  prac- 
ticed where  possible  with  potatoes  or  similar  crop. 

Two  species  of  root-aphides  do  great  damage.  They  are  the 
beet  aphis  and  beet  root-aphis. 

The  Beet  Aphis  (Pemphigus  betce  Doane)  ruined  in  one  year 
in  a  single  valley  upwards  of  1,000  tons  of  beets.  This. was  in 
Oregon.  The  species  also  inhabits  Washington,  and  probably 
California,  and  it  is  probable  that  it  may  be  reckoned  among 
the  important  beet  pests  of  the  future. 

Owing  to  the  large  acreage  in  sugar-beet  growing  regions  of 
the  United  States  we  cannot  successfully  control  the  root-aphides 
by  means  of  insecticides.  It  would  be  supposed  naturally  that 
heavy  flooding  and  plowing  in  fall  so  as  to  expose  the  insects 
to  the  frost  might  control  it,  but  this  is  sometimes  a  failure. 
Our  knowledge  of  alternate  food  plants  is  somewhat  limited, 
but  we  can  recommend  the  avoidance  of  beet  cultivation  in  land 
where  other  plants  subject  to  the  attack  of  this  insect  have 
grown;  also  crop  rotation.  If  the  aphides  are  found  at  work 
only  in  parts  of  a  field,  they  could  be  destroyed  here  with 
kerosene  emulsion  applied  preferably  just  before  rainfall,  or  by 
following  the  application  with  a  flooding  of  water. 

Root-aphides  are  almost  invariably  associated  with  ants, 
which  foster  them  and  act  as  distributers  of  infestation  by  car- 
rying wingless  forms  from  plant  to  plant.  It  is  therefore  ad- 
visable to  break  up  the  nests  of  ants  as  fast  as  they  are  found. 


I30  INSECTS    INJURIOUS   TO   VEGETABLES 

The  Beet  Root-aphis  (Tyclica  hrevicornis  Hart,  fig.  82)  is 
most  destructive  in  Colorado.  It  has*  a  variety  of  alternate  food 
plants,  and  we  can  only  learn  by 
experiment  what  are  the  best  for 
rotation.  We  should  avoid  corn, 
sorghum,  and  other  cereals,  grasses, 
and  particularly  should  we  avoid 
weeds,  including  wild  grasses.  Oth- 
erwise the  remedies  advised  for  the 
beet-aphis  are  suggested. 


^  '  WHITE    GRUBS    AND 

Fig.    82.-..   Bean  roo^aphis;    b,  WIREWORMS 

antenna;c,tarsus.  Enlarged.  (After         ^     number     of     fotms     of     white- 
Carman. ) 

grubs  and  of  wireworms  attack 
beet  roots,  but  none  appear  to  favor  this  form  of  food.  We 
have  yet  to  learn  of  severe  and  extensive  damage  by  them. 

Remedies. — Among  the  best  remedies  are  fall  plowing,  rota- 
tion of  crops,  clean  cultivation,  in  particular  the  suppression  of 
grasses,  the  use  of  potash  fertilizers  as  stimulants  to  the  plants 
found  affected,  all  of  these  remedies  acting  to  a  certain  extent 
on  both  forms  of  insects. 

In  this  chapter  there  have  been  considered  quite  briefly  the 
principal  forms  of  insects  which  trouble  the  beet-grower  or 
which  he  may  expect  to  meet  in  his  fields.  Several  of  the  in- 
sects mentioned  in  the  last  four  pages  require  additional  in- 
vestigation before  definite  and  detailed  instructions  can  be 
furnished  for  their  suppression.  For  further  information  appli- 
cation should  be  made  to  the  Bureau  of  Entomology  of  the 
Department  of  Agriculture. 


CHAPTER    IX 

INSECTS    INJURIOUS    TO    CABBAGE    AND 
OTHER   CRUCIFEROUS    CROPS 

Cabbage  is  peculiarly  susceptible  to  insect  attack,  and  there 
are  probably  more  species  of  insects  that  injure  it  than  any  other 
truck  crop.  Other  edible  cole  plants  are  attacked  by  the  same 
species  of  insects,  but  as  a  rule  suffer  rather  less  injury.  At- 
tack begins  from  the  time  the  seeds  commence  to  sprout  and 
continues  in  the  case  of  cabbage  until  the  edible  product  is  ready 
for  cooking. 


Fig.  83.— Cabbage  root-maggot,   a  _La;va;  i,  puparium,  dorsal  view;  c,  female  fly;  d,  head 
of  male;  e,  antenna-     All  enlarged.     (After  Riley,  U-  S.  Dept.  Agr.) 

ROOT-MAGGOTS 

The  Cabbage  Maggot  (Pegomya  brassiccc  Bouche). — The 
roots  of  cabbage  and  related  cruciferous  crop  plants  frequently 
suffer  severe  injury  from  the  attack  of  the  cabbage  maggot 
(fig.  83).     Young  plants  are  most  seriously  affected,  the  mag- 

131 


132  INSECTS    INJURIOUS   TO   VEGETABLES 

gots  eroding  the  outer  surface  and  boring  into  the  interior  of 
the  roots,  devouring  the  tender  rootlets  and  frequently  pene- 
trating into  the  lower  portion  of  the  stalk.  This  insect,  known 
also  as  radish  maggot,  is  an  imported  pest.  It  does  serious 
injury  throughout  the  northern  tier  of  States  and  Canada,  at- 
tacking all  forms  of  crucifers.  It  is  the  cause  of  more  or  less 
loss  to  these  crops  each  year.  Since  1902  it  has  not  only  been 
exceedingly  destructive,  but  has  increased  in  injuriousness  from 
year  to  year.  Frequently  entire  crops  over  considerable  areas 
are  completely  destroyed.  Two  or  three  generations  of  this 
maggot  are  indicated  where  it  has  been  observed. 


The  remedies  prescribed  for  the  seed-corn  maggot  are  ap- 
plicable. In  addition  there  are  certain  preventive  and  other 
measures  for  its  destruction  that  have  been  found  successful, 
their  use  being  justified  by  the  great  value  of  cabbage  plants. 

Carbolic-acid  emulsion,  prepared  as  prescribed  on  page  37, 
and  diluted  about  35  times,  is  applicable  when  this  maggot  oc- 
curs on  radish. 

Hand-picking,  although  laborious,  has  the  merit  of  effective- 
ness, and  is  useful  on  cabbage,  although  not  practicable  on 
radish  and  similar  crops.  It  consists  in  pulling  up  the  young 
plants,  examining  the  roots  for  eggs  and  maggots,  and  either 
destroying  the  eggs  and  maggots  by  crushing  with  the  hand  or 
by  washing  the  roots  in  a  strong  solution  of  soap  and  then 
replanting.  In  most  ca.ses  the  plants  show  no  ill  effects  from 
this  treatment  after  two  or  three  weeks  have  elapsed. 

Methods  of  cultivation. — Comparatively  little  can  be  expected 
from  various  farming  methods  which  are  safeguards  against 
other  insects.  Keeping  the  soil  well  hilled  around  the  cabbage 
plants  develops  more  roots,  thus  affording  more  food  for  the 
maggots  and  leaving  enough  roots  to  strengthen  the  plant  itself. 
Crop  rotation  should  be   followed  with   any  plants  other   than 


INSECTS    INJURIOUS    10  C.aBi3AGE  AND  OTHER  CROPS      I33 


crucifers  or  onions.  With  these  latter  it  is  inadvisable,  as  the 
same  atmospheric  or  other  conditions  which  induce  injury  by 
the  cabbage  maggot  seem  to  operate  in  increasing  the  numbers 
of  the  onion  pest,  which  has  a  similar  distribution.  Fall  plowing 
is  advisable  and  cabbage  stumps  should  be  removed  and  de- 
stroyed, especially  early  in  the  season. 

Bisnlphid  of  carbon  treatment.— In  case  tarred  paper  cards, 
which  will  next  be  described,  or  other  preventive  methods  are 
not  employed,  bisulphid  of  carbon  may  be  used.     It  should  be 


Fig    84.— Bisulphid  of  carbon  injector 
in  use 


Fig.  85.— Tarred  paper  card  in 
outline.  One-half  size.  (After 
Goff.) 


applied  below  the  root  system  with  a  special  injector  or  syringe,^ 
taking  care  that  the  application  is  not  made  directly  to  the 
plants,  as  it  is  likely  to  kill  them.  A  hole  is  made  a  little 
distance  (3  or  4  inches)  from  the  plant,  and  the  injector  in- 
serted at  an  angle,  as  shown  in  figure  84.  After  injecting  the 
liquid  the  instrument  should  be  withdrawn  and  the  hole  closed 
by  packing  with  the  foot.  From  a  teaspoonful  to  a  tablespoon- 
ful  to  each  young  plant,  and  a  single  application,  is  generally 
sufficient. 

Tarred  paper  cards. — The  use  of  disks  or  pads  of  tarred  paper 

1  The  McGowen   injector,   no  longer  for   sale,  has  proved  very  successful. 


134 


INSECTS    INJURKK'S    TO   VEGETABLES 


for  the  protection  of  cabbage  against  the  oviposition  of  the  fly 
was  perfected  in  1889  by  Mr.  W.  H.  Goff. 

The  cards  are  cut  in  hexagonal   form    (fig.  85).  in  order  to 
economize  material,  and  a  thin  grade  of  tarred  paper  is  used,  as 
the  cards  made  from  it  are  more  readily  placed 
about  the  plant   without  being  torn.     The  blade 
of  the  tool,  which  can  be  made  by  a  blacksmith, 
is  formed  from  a  band  of  steel,  bent  in  the  form 
of   a   half   hexagon,   and   then   taking   an   acute 
angle,  reaches  nearly  to  the  center,  as  shown  in 
I      \/\\        figure  86.     The  part  making  the  star-shaped  cut 
«  \\       is    formed    from    a    separate    piece    of    steel,    so 

attached  to  the  handle  as  to  make  a  close  joint 
with  the  blade.  The  latter  is  beveled  from  the 
outside  all  around,  so  that  by  removing  the  part 
making  the  star-shaped  cut  the  edge  may  be 
ground  on  a  grindstone.  It  is  important  that  the 
angles  in  the  blade  be  perfect,  and  that  its  out- 
line represent  an  exact  half  hexagon. 

To  use  the  tool,  place  the  tarred  paper  on  the 
end  of  a  section  of  wood  and  first  cut  the  lower 
edge  into  notches,  as  indicated  in  figure  87,  using 
only  one  angle  of  the  tool.  Commence  at 
the  left  side,  and  place  the  blade  as  indicated  by  the  dotted  lines, 
and  strike  at  the  end  of  the  handle  with  a  light  mallet,  and  a 
complete  card  is  made.     Continue   in  this  manner  across  the 


Fig.  86— Tool  for 
cutting  cards. 
About  one-fourth 
size. (After  Goff.) 


Fig.  87.— Showing  how  tool  is  used,  dotted  line  indicating  position 
of  edge  of  tool.    (After  Goff) 


INSECTS    INJURIOUS    TO  CABBAGE  AND  OTHER  CROPS      I35 

paper.  The  first  cut  of  every  alternate  course  will  make  an 
imperfect  card,  and  the  last  cut  in  any  course  may  be  imperfect, 
but  the  other  cuts  will  make  perfect  cards  if  the  tool  is  correctly 
made  and  properly  used.  The  cards  should  be  placed  about  the 
plants  at  the  time  of  transplanting.  To  place  the  card,  bend  it 
slightly,  to  open  the  slit,  then  slip  it  on  the  center,  the  stem 
entering  the  slit,  after  which  spread  the  card  out  flat,  and  press 
the  points  formed  by  the  star-shaped  cut  snugly  afound  the  stem. 

A  Wisconsin  grower  protected  7.000  plants  and  secured  a 
splendid  crop,  while  unprotected  plants  nearby  would  have  been 
a  complete  failure  if  the  maggots  had  not  been  picked  ofif  by 
hand.  Others  have  reported  similar  success.  One  lost  only  25 
plants  out  of  10,000  to  15,000  that  he  protected  with  the  cards, 
where  ordinarily  he  would  have  lost  from  75  to  90  per  cent,  of 
the  crop. 

The  tarred  cards  are  applicable  to  cabbage  and  cauliflower 
only,  but  it  is  claimed  by  those  who  have  employed  them  that 
they  are  cheaper,  more  practicable,  and  more  efficient  than  any- 
thing as  yet  devised  for  preventing  the  ravages  .of  the  cabbage 
maggot.  Success  in  using  them  is  dependent  upon  their  being 
properly  applied,  to  fit  tightly,  so  that  the  fly  is  unable  to  obtain 
access  to  the  stem  for  the  deposition  of  her  eggs.  Cards  must 
be  renewed  and  their  use  continued  for  each  maggot  year  to  be 
effective. 

Coverings  and  hellebore. — Some  success  has  also  been  attained 
by  covering  young  plants  in  seed-beds  with  netting  and  by  ap- 
plying hellebore  about  the  roots. 

The  Seed-corn  Maggot  (Pegomya  fnsciceps  Zett.). — This 
species,  previously  considered  on  page  106  on  bean  and  pea 
insects  has  been  identified  with  attack  to  cabbage,  turnip  and 
radish  on  numerous  occasions  and  in  many  localities.  When 
occurring  on  such  plants  it  should  be  treated  in  about  the  same 
method  as  the  cabbage  maggot. 


136  INSECTS    INJURIOUS    TO   VEGETABLES 

CABBAGE   WORMS 
The  Imported  Cabbage  Worm  (Pontia  rapce  Linn.). — This  is 
the  worst  of  all  cabbage  pests  and  one  of  the  most  important 
of  all  truck  insects.     It  is  altogether  too  well  known  through- 


Fig.  Zt.— Pontia  raps,  a,  Female  butterfly;  b,  egg;  c,  larva  on  cabbage  leaf;  d,  sus- 
pended chrysalis,  a,  c,  d.  Slightly  enlarged;  b,  more  enlarged.  (Author's  illustration, 
U.  S.  Dept.  Agr.) 

out  North  America  and  Europe,  and  the  white  butter- 
fly is  quite  generally  recognized  as  its  parent.  The  cater- 
pillar is  velvety  green  and  measures,  when  full  grown,  about 
an  inch  and  a  quarter,  presenting  the  appearance  shown  in 
figure  88,  c.  The  butterfly  has  a  wing  expanse  of  nearly  two 
inches,  and  is  white,  marked  with  black  near  the  tips  of  the 
fore-wings.  The  female  (a)  has  two  conspicuous  black  spots 
on  each  fore-wing,  the  male  has  only  one.  This  cabbage  worm 
is  the  bane  of  every  cabbage-grower,  and  the  dread  of  every 


INSECTS    INJURIOUS    TO  CABBAGE  AND  OTHER  CROPS      I37 

careful  cook  and  housewife.  It  begins  work  early  in  the  season, 
when  the  principal  damage  is  usually  accomplished,  and  after 
riddling  the  outer  leaves,  attacks  the  more  tender  inner  leaves 
as  they  form,  frequently  secreting  itself  in  the  heads,  which 
are  made  most  unsightly  by  its  excrement.  This  species  was 
first  observed  in  the  United  States  in  1865  and  in  about  a  score 
of  years  it  had  invaded  nearly  every  state  and  territory  in  our 
domains. 

All  cruciferous  crops,  but  particularly  cabbage  and  cauli- 
flower, are  attacked,  as  are  also  nasturtium,  mignonette  and 
some  allied  plants.  The  butterflies  are  on  the  wing  from  early 
morn  till  dusk.  As  early  as  March  they  can  be  seen  flying  about 
cabbage  fields  and  they  continue  until  after  severe  frosts.  The 
observed  egg  period  is  from  4  to  8  days.  The  larva  eats 
voraciously  and  grows  with  rapidity,  attaining  full  growth  in 
from  10  to  14  days  after  hatching.  The  summer-time  chrysalis 
period  is  from  7  to  14  days,  but  the  last  chrysalides  remain 
undeveloped  until  the  following  spring.  The  life  cycle  has 
been  traced  from  between  22  days  to  five  weeks.  Even  in  New 
England  this  species  is  credited  with  being  triple  brooded,  but 
in  the  District  of  Columbia  and  vicinity  there  must  be  one  or 
more  additional  generations,  and  there  is  a  possibility  of  still 
more  in  the  extreme  South. 

A  natural  enemy  of  this  species,  Pteromahts  piiparum,  is 
shown  in  figure  89,  and.  a  "worm"  parasitized  by  Apantcles 
glomeratus  is  illustrated  by  figure  90. 


In  treating  this  species  it  should  be  borne  in  mind  that  other 
"worms"  and  pests  are  more  often  present  than  otherwise. 

Arsenicals. — The  best  remedy  is  Paris  green  applied,  prefer- 
ably as  a  spray,  at  the  rate  of  about  one  pound  of  poison  to 
150  gallons  or  less  of  water,  and  it  should  be  used  when  plants 
are  first  set  out,  to  insure  its  reaching  the  young  "worms"  be- 


138 


INSECTS    INJURIOUS   TO   VEGETABLES 


fore  they  have  burrowed  far  into  the  heads.  Other  appHcations 
should  follow  frequently,  as  required,  and  can  be  made  with 
safety  until  the  heads  are  about  half  formed,  and  even  later,  as 
the  poison,  under  ordinary  circumstances,  disappears  from  the 
plants  two  or  three  weeks  after  being  applied. 

Bran  mash  is,  according  to  the  testimony  of  some,  successful 
against  cabbage  worms.  It  is  prepared  in  the  same  manner  as 
for  cutworms  and  grasshoppers.     See  page  55. 

Kerosene  emulsion   is  not  as  efficient  as  arsenicals,  because 


Fig.  i,9.—Pteromalus puparum.  Female. 
Highly  magnified.  (Author's  illustra- 
tion, U.  S.  Dept.  Agr.) 


Fig.  90-— Parasitized  cabbage  worm  {Pontia 
rapas).  showing  cocoon  mass  of  Apanfeles 
glomeratus  below.  (Author,  U.  S.  Dept- 
Agr.) 

it  is  necessary  for  this  spray  to  come  into  direct  contact  with 

the  "worms." 

Pyrethrum  has  the  advantage  of  not  being  poisonous  to 
humans,  but  is  said  by  some  cabbage  growers  to  discolor  the 
leaves,  and  if  its  use  is  not  continued  at  frequent  intervals  the 
"worms"  recover.  It  is  more  expensive  than  remedies  that  have 
been  mentioned. 

Hot  water  at  a  temperature  of  about  130°  F.  does  practically 
no  harm  to  plants  and  destroys  all  insects  with  which  it  comes 
in  contact. 

Clean  cultivation  and  trap  crops. — If  united  effort  in  clean 
farming  could  be  secured,  together  with  the  use  of  arsenicals, 
the  losses  due  to  the  ravages  of  this  and  other  leaf-feeding 
cabbage  pests  might  be  largely  averted.    The  practice  of  leaving 


INSECTS    INJURIOUS   TO  CABBAGE  AND  OTHER  CROPS      I39 

cabbage  stalks  in  the  field  after  the  crop  has  been  secured  is 
reprehensible.  Remnants  should  be  destroyed,  with  the  exception 
of  a  few  left  at  intervals  through  a  field  as  traps  for  the  females 
for  the  deposition  of  their  eggs.  These  plants  should  be  freely 
poisoned  with  arsenicals,  so  that  the  last  generation  will  not 
develop. 

The  Southern  Cabbage  Butterfly  {Pontia  protodice  Boisd.).— 
Before  the  advent  of  the  imported  cabbage  butterfly,  the  present 
species   was  the  occasion   of   considerable   injury,   particularly 


Fig.  9 1  .—Southern  cabbage  butterfly 
worm.    (After  Riley) 


Fig.  92.— Potherb  butterfly.    Adult  above, 
larva  below.    (After  Harris) 


southward.  Of  late  it  has  disappeared  in  many  regions,  but 
occasionally  makes  its  reappearance  for  a  limited  period.  In 
many  respects  it  resembles  the  preceding,  and  the  male  as  it  is 
seen  flitting  lazily  through  cabbage  fields  and  gardens  would 
never  be  recognized  as  distinct  from  the  more  injurious  form. 
The  "worm"  (fig.  91)  varies  from  pale  to  dark  blue  or  green, 
is  striped  with  yellow  and  covered  with  black  spots  bearing 
black  hairs. 

Remedies. — The  treatment  is  the  same  as  for  the  preceding. 

The  Potherb  Butterfly  {Pontia  napi  Linn.). — This  butter- 
fly is  found  in  the  more  northern  and  eastern  portions  of 
North  America,  and  is  distinguished  from  others  attacking  cole 
crops  by  its  nearly  uniform  white  wings  without  spots.  The 
larva    (fig.  92)    is  uniform  pale  green,  and  resembles  the  cab- 


I40 


INSECTS    INJURIOUS    TO   VEGETABLES 


bage  leaves  on  which  it  feeds.  It  devours  the  pulp  on  the  lower 
surface,  often  leaving  the  veins  intact. 

This  species  has  evidently  been  decimated  in  the  same  man- 
ner as  the  southern  cabbage  butterfly  by  the  foreign  invader, 
Poiitia  rapcc,  and  is  now  seldom  found  save  on  wild  plants. 

Remedies  are  the  same  as  for  the  imported  cabbage  butterfly. 

The  Cross-striped  Cabbage  Worm  {Evcrgestis  rimosalis 
Guen.). — Thus  far  have  been  considered  only  the  "worms" 
produced  by  butterflies.     The  species  figured  and  those  which 


Fig.  93.— Cross-striped  cabbage  worm,  a.  Moth;  b,  egg  mass;  c.  sculpture  of  egg; 
d  'worm  ' ;  e.  cocoon,  a,  d,  e.  Twice  natural  size,  b.  c,  more  enlarged.  (Author's 
illustration,  U.  S.  Dept.  Agr.) 

follow  are  all  the  progeny  of  moths.  This  "worm"  injures  cab- 
bage and  its  varieties  in  nearly  the  same  manner  as  does  the  im- 
ported cabbage  worm,  attacking  the  heads  and  digging  deeply 
into,  and  eating  out,  the  hearts.  While  plants  are  tender  this 
destroys  them  for  the  market  or  table.  This  species  is  as  a  rule 
less  injurious  to  other  crucifers  (fig.  93). 

Remedies. — The  remedies  advised  as  best  for  the  imported 
cabbage  worm  are  equally  applicable  to  this  species. 

The  Common  Cabbage  Looper  {Autographa  brassicce  Riley). 
— Late  cabbage  particularly  southward  is  much  subject  to  injury 
by  the  looper  or  cabbage  "plusia"  which  is,  next  to  the  imported 


INSECTS  INJURIOUS  TO  CABBAGE  AND  OTHER  CROPS   I4I 

cabbage  worm  and  the  harlequin  bug,  our  most  important  insect 
enemy  of  cruciferous  crops.  It  is  unusually  voracious,  devel- 
oping rapidly,  but  is  kept  under  partial  control  by  natural  in- 
fluences, and  therefore  subject  to  extreme  fluctuation  in  num- 
bers, doing  great  damage  for  one  or  more  seasons  in  some 
localities,  and  remaining  absent  from  them  for  a  number  of 
succeeding  years. 

The  insect  derives  its  name  from  the  peculiar  habit  of  its 
larva  of  "looping"  like  a  measuring  worm,  due  to  the  lack  of 
legs  on  the  third  and  fourth  joints  of  the  abdomen.  The  moth 
which  produces  it  is  shown  in  figure  9,  a.  The  "looper"  is  at 
first  a  pale-green,  fragile-looking  creature,  and  varies  in 
color  when  mature,  being  strongly  marked  with  white  lines, 
shown  in  figure  9,  c.  It  constructs  for  pupation  a  white,  gauzy 
cocoon,  d,  which  is  usually  attached  to  the  broad  surface  of 
a  leaf.  The  cabbage  looper  is  well  distributed  throughout  that 
part  of  the  United  States  lying  east  of  the  Rocky  Mountains, 
and  is  more  destructive  in  the  South  than  in  the  northern  States. 
It  is  most  troublesome  to  cabbage,  but  affects  all  crucifers  and 
at  times  does  great  injury  to  peas,  beets,  celery  and  lettuce,  and 
feeds  also  on  tomato,  potato  and  less  frequently  on  asparagus 
and  clover.  It  sometimes  does  damage  to  carnation,  mignonette, 
and  German  ivy  in  greenhouses. 

The  species  is  apparently  three-brooded  on  Long  Island  and 
in  the  District  of  Columbia,  and  hibernation  takes  place  chiefly 
in  the  pupal  stage.  Few  individuals  survive  the  winter  north- 
ward, but  the  propagation  of  the  species  is  so  rapid  that  by  the 
time  autumn  is  reached  great  numbers  of  loopers  are  produced 
which  do  much  damage  to  crops  in  cultivation  at  this  time.  This 
insect  is  very  susceptible  to  diseases  and  to  parasitism.  A  par- 
asitized looper  is  shown  by  figure  94. 

Methods  of  Control  employed  for  other  cabbage  worms  are 
useful  against  loopers.  Remedial  measures  should  be  continued 
with  persistency  at  frequent  intervals  in  order  to  insure  sue- 


142  INSECTS    INJURIOUS    TO    VEGETABLES 

cess,  and  arsenicals  should  be  a^Dplied  when  possible  to  the  lower 
surface  of  the  outer  leaves  to  destroy  all  the  insects.  If  the 
first  generations  could  be  killed  off  there  would  be  less  difficulty 
in  keeping  the  insect  in  subjection.  Paris  green  mixed  with 
lime  or  other  diluent  has  been  used  dry  with  some  success,  but 
is  less  efficient  than  for  the  imported  cabbage  worm.  Dry  ap- 
plications do  not  reach  the  lower  surface,  hence  a  spray  is 
preferable.  The  larger  loopers  eat  through  the  leaves,  but  when 
they  find  anything  distasteful  they  cease  feeding  and  search  for 
tissue  that  has  not  been  poisoned.  After  rainfall  eggs  hatch 
and  the  poison  having  been  washed  away  the  larvae  continue 
feeding.  Sirrine  obtains  good  results  with  resin-lime  mixture.  It 
requires  about  two  hours  to  make  this  mixture,  and  considerable 


Fig.  94.— Cabbage  boper  carasitized  by  Copidosoma  'runcakUa     Slightly  enlarged 
(After  Riley,  U.  S.  Dept.  Agr  J 


care  is  necessary  in  its  preparation;  but  when  crops  are  grown 
on  a  large  scale  it  might  pay  to  use  this  remedy.  It  has  the 
advantage  of  being  more  adhesive  than  a  Paris  green  spray, 
remaining  on  the  under  surfaces  as  well  as  upper  leaves  and 
requiring  two  or  three  heavy  rains  to  remove  all  of  it,  even  on 
the  exposed  portions  of  leaves.  Arsenate  of  lead  has  similai 
adhesiveness,  and  as  it  has  given  good  results  in  experiments 
on  a  small  scale  it  should  receive  further  tests. 

The  Imported  Cabbage  Webworm  (Hellula  undalis  Fab.). — 
As  if  the  cabbage-grower  did-  not  have  enough  "worms"  with 
which  to  contend  a  new  species  has  recently  appeared  in  the 
South,  and  there  is  now  the  threatened  danger  of  its  introduc- 
tion farther  north  in  the  same  manner  as  has  happened  in  the 


INSECTS    INJURIOUS    TO  CABBAGE  AND  OTHER  CROPS      I43 

case  of  the  cabbage  looper  and  harlequin  cabbage  bug.  The 
species  under  consideration,  the  imported  cabbage  webworm, 
should  it  increase  in  destructiveness  and  enlarge  its  area,  bids 
fair  to  become  a  troublesome  species,  as  it  is  difficult  to  treat. 
The  moth  (fig.  95,  o)  is  gray,  with  the  fore-wings  mottled 
with  black,  white  and  brown.     The  expanse  of  wing  is  about 


Fig.  95.— Cabbage  webworm.    a,  Mature  moth;  b   larva,  lateral  view;  c,  larva,  dorsal 
view;  d,  pupa     All  three  times  natural  size.    (Author's  illustration,  U.  S-  Dept.  Agr.) 


five-eighths  of  an  inch.  The  mature  larva  (fig.  95,  b,  c)  is  a 
little  more  than  half  an  inch  long,  in  color  dull  yellowish-gray, 
striped  with  broad,  brownish-purple  longitudinal  bands.  The 
moth  is  described  as  laying  her  eggs  in  the  "bud"  of  cabbage, 
or  turnip,  and  the  larva  soon  after  hatching  spins  a  web  over 
itself,  leaving  a  hole  for  egress.  From  the  protection  afforded 
by  this  domicile  the  larva  feeds,  rehiring  into  the  web  when  its 
hunger  is  appeased.  When  larvae  are  particularly  numerous 
three  or  four  days  suffice  for  the  destruction  of  a  turnip  or  cab- 
bage patch,  the  plants  rotting,  or  in  the  case  of  turnip  failing 
to  develop  roots,  and  this  with  their  excrement  which  adheres 


144  INSECTS    INJURIOUS    TO    VEGETABLES 

to  the  plants,  forms  a  more  or  less  perfect  place  of  concealment 
for  them. 

Remedial  Measures. — A  spray  of  Paris  green  applied  as  soon 
as  the  larva  hatches  serves  in  great  measure  to  control  it.  Clean 
cultural  methods  should  be  persistently  practiced,  and  every  bit 
of  refuse  material,  particularly  cabbage  stalks  and  weeds,  should 
be  raked  up  into  piles  and  set  afire  by  adding,  if  necessary,  dry 
straw  to  aid  in  their  ignition.  Kerosene  emulsion,  properly 
prepared  and  applied  sufficiently  often  to  insure  a  permanent 
odor,  should  be  effective  in  preventing  egg  laying  and  will  also 
destroy  other  insects  with  which  it  may  come  in  contact. 

The  Diamond-back  Moth  (Plutella  maculipennis  Curtis) . — One 
of  the  minor  enemies  of  cabbage  is  the  larva  of  the  imported 
diamond-back  moth  or  "cabbage  plutella."  It  is  smaller  than 
any  of  the  preceding,  and  as  a  rule  its  injuries  are  much  less 
conspicuous.  Occasionally,  however,  it  becomes  '  sufficiently 
numerous  as  to  be  quite  troublesome.  Its  minute  active  cater- 
pillar may  be  found  on  cabbage  everywhere,  and  in  this  stage 
as  well  as  in  pupa,  when  it  rests  in  a  beautiful  white,  lace-like 
cocoon  attached  to  the  surface  of  cabbage  leaves,  it  is  familiar 
to  observing  persons.  Attack  is  usually  confined  to  the  outer 
leaves,  the  larva  feeding  generally  on  the  lower  surface  and 
not  eating  through,  as  with  the  larger  looper  and  some  other 
worms.  At  times,  however,  leaves  are  riddled  with  holes  and 
much  of  their  substance  devoured. 

The  moth  (fig.  96,  /)  is  gray  and  distinguished  by  the  black- 
marked  fore-wing.  The  wing  expanse  is  about  three-fifths  of 
an  inch.  This  insect  is  found  during  winter  on  old  cabbage 
stalks,  hibernation  taking  place  normally  as  pupa,  although 
adults  also  occur  as  late  as  December.  Two  or  three  genera- 
tions are  produced  in  the  more  northern  States,  and  farther 
south  four  or  five  broods  occur  during  a  season.  In  the  extreme 
South  the  insect  occurs  throughout  the  year. 


INSECTS  INJURIOUS  TO  CABBAGE  AND  OTHER  CROPS      I45 

Remedies. — The  simpler  cabbage  worm  remedies  are  suffi- 
cient in  ordinary  cases.  Pyrethrum  is  valuable  as  is  also  kero- 
sene emulsion,  but  Paris  green,  unless  applied  as  an  under- 
spray,  which  is  difficult  with  most  cruciferous  crops,  is  reported 
not  so  effective. 

Cutworms  will  attack  cabbage,  turnip,  and  similar  plants 
when  available,  and  there  are  a  number  of  caterpillars,  other 
than  those  which  have  been  considered,  which  do  great  damage 


Fig.  96.— Diamond-back  moth,  a.  Larva;  b,  c.  segments  of  same;  d,  pupa;  e,  pupa  in 
cocoon;  /.  h,  moth;  g.  wings  of  dark  form  of  moth;  /,  last  segment  of  pupa-  All  en- 
larged.   (After  Riley.  U.  S.  Dept.  Agr.) 


to  these  crops.  When  cutworms  become  abundant  late  in  the 
season,  plants  are  damaged  in  the  same  manner  as  by  the 
imported  cabbage  worm,  by  eating  the  more  tender  portions  and 
penetrating  into  the  hearts.  Severe  injury  is  often  reported, 
e.  g.,  in  one  garden  only  30  plants  out  of  600  escaped,  while 
it  is  not  uncommon  to  lose  half  or  more  of  the  plants  early  in 
the  spring.  The  fall  army  worm,  salt-marsh  caterpillar  and 
"woolly  bears"  frequently  attack  cole  crops,  and  the  first 
mentioned  when  numerous  does  damage  of  great  seriousness. 
The  zebra  and  clover  caterpillars  appear  to  favor  these  crd^s 
among  others  grown  in  gardens,  and  the  garden  webworm  also 
affects  them.    These  species  are  treated  in  preceding  chapters. 


146 


INSECTS    INJURIOUS    TO   VEGETABLES 


FLEA-BEETLES  AND  LEAF-BEETLES 

An  unusual  number  of  flea-beetles  are  reckoned  among 
enemies  of  cruciferous  crops.  No  less  than  seven  species  (of 
PJiyllotreta)  are  more  or  less  attached  to  this  class  of  plants 
and  although  like  other  flea-beetles  they  are  as  a  rule  only 
periodically  troublesome,  they  are  in  their  abundant  seasons 
foes  of  no  little  importance.  The  characteristics  of  flea-beetles 
have  been  described  on  page  63.  The  cabbage-feeding  forms 
are  mostly  quite  minute,  none  measuring  more  than  an  eighth 
of  an  inch. 

The  Striped  Turnip  Flea-beetle  (Phyllotrcta  vittata  Fab.).' — 
The  commonest  and  most  destructive  flea-beetle  living  on 
cruciferous  crops  is  the  species 
above  mentioned.  It  is  found 
throughout  the  warmer  months, 
and  attacks  most  crucifers,  cul- 
tivated and  wild.  As  it  is  sub- 
ject to  great  fluctuation  in  num- 
bers, it  cannot  be  compared  to 
the  imported  cabbage  looper  or 
harlequin  bug,  yet  it  is  capable 
of  severe  injuries  and  crucifer- 
ous crops  are  seldom  free  from 
it  within  its  range,  which  is 
extensive.  The  beetle  (fig.  97, 
b)  is  polished  black  in  color, 
and  each  wing-cover  is  ornamented  with  a  broad,  wavy  band 
of  pale  yellow. 

This  species  is  indigenous  to  the  Atlantic  region,  where  it  is 
most  abundant,  but  has  been  diffused  by  commerce,  until  now 
it  is  found  in  most  States  and  Territories  from  Maine  to  the 
Gulf  and  Pacific  States. 

Remedies. — When  cabbage  and  other  crucifers  are  treated 
with  arsenicals  for  "worms"  no   further  remedy  is  necessary 


Fig.  97.— Striped  turnip  beetle,    o.  larva 
6,  beetle.  (Riley,  U- S.  Dept.  Agr) 


INSECTS  INJURIOUS  TO  CABBAGE  AND  OTHER  CROPS      I47 


for  flea-beetles.  It  adds  to  the  effectiveness  of  Paris  green, 
however,  to  use  Bordeaux  mixture  as  a  diluent,  as  the  latter 
in   addition   to   being   a    fungicide   is   a   powerful   deterrent   of 


Fig-  98.— Water-cress  leaf-beetle  (Phxdon  seruginosd).    a.  Adult;  b,  larva;  d.  pupa 
Enlarg:d  six  times.    (Author's  illustration,  U-  S-  Dept.  Agr.) 

flea-beetles.      See    page    65    on    remedies    for    leaf-beetles    and 
flea-beetles. 

The  Water-cress  Leaf-beetle  (Phcedon  cvniginosa  Suffr.) 
has  been  reported  injurious  to  water-cress  since  1903.  It  is  a 
small,  metallic  blackish  beetle  (fig.  98)  and  with  the  water-cress 
sowbug  (figured  on  page  4)  is  a  pest  on 
the  plant  from  which  they  have  both  re 
ceived   their   English   name.^ 

The  Western  Cabbage  Flea-beetle  (Phyl- 
lotrcta  pusilla  Horn.). — In  some  of  the 
western  States  not  yet  inhabited  by  either 
of  the  preceding  there  is  a  smaller,  dark- 
colored  flea-beetle  which  sometimes  does 
great  damage  to  crucifers  and  many  other 
crops. 

This    flea-beetle    is    of    a    uniform    deep  pjg    99.— western  cab- 
polished  olive-green  color,  and  the  surface     bage  fiea-beetie.    Much 

,      ,  T-  ,  enlarged.     (After  Riley, 

IS  irregularly  punctate.     It  measures  about     u.  s.  Dept.  Agr.) 
seven-hundredths  of  an  inch  in  length.     It . 
ranges  from  the  Dakotas  to  Mexico,  and  westward  to  Southern 
California  and  is  often  found  in  great  numbers. 

1  Information   concerning  both   species  is   furnished  in   Bui.   No.   66,   Pt.   II, 
Bu.   Entom.,   U.    S.    Dept.   Agr. 


148  INSECTS   INJURIOUS    TO    VEGETABLES 

Remedies. — Owing  to  the  peculiarity  of  this  species  of  con- 
gregating in  immense  numbers  and  doing  great  damage  in  a 
short  time,  immediate  steps  for  its  suppression  must  be  taken. 
Remedies  advised  for  the  striped  turnip  flea-beetle  are 
applicable. 

PLANT-BUGS   AND    APHIDES 

The  HarlecLuin  Cabbage  Bug  (Murgantia  histrionica  Hahn.). — 

From  southern  New  York  and  01\io  southward,  late  cabbage 

and  other  cole  crops  sometimes  suffer  severely   from  a  gayly 

colored  plant-bug  variously  known  as  the  calico  back,  fire  bug. 


Fig.  100.— Harlequin  cabbage  bug.  a.  Young;  b.  half  grown;  c.  d,  egg  cluster;  e.  same 
from  above;/.  ^,  adult,  c,  /,  g,  Natural  size;  a,  b,  slightly  enlarged;  d.  e  more  en- 
larged.   (After  Riley.) 

and  terrapin  bug,  as  well  as  harlequin  cabbage  bug.  It  is  the 
most  destructive  cabbage  pest  of  the  South,  and  second  only 
to  the  imported  cabbage  worm  as  an  enemy  to  the  cole  crops 
of  our  country.  It  is  a  native  of  Mexico  and  Central  America 
and  since  its  discovery  in  Texas  in  1866  its  dissemination  north- 
ward and  eastward  has  been  rapid,  until  at  one  time  it  threatened 
to  overrun  southern  portions  of  New  York  and  New  England, 
Ohio  and  States  farther  westward.  The  harlequin-like  ornamen- 
tation of  the  insect  is  shown  in  figure  100,  /.  g.;  the  dark 
portions  are  shining  black  or  dark  blue  and  the  lighter  portions 


INSECTS  INJURIOUS  TO  CABBAGE  AND  OTHER  CROPS      I49 

bright  yellow  or  red.  The  eggs  (d)  are  beautiful  objects, 
looking  like  miniature  white  barrels  bound  with  black  hoops, 
and  with  black  spots  set  in  the  proper  place  for  bung-holes. 

This  insect  accomplishes  its  work  of  destruction  by  sucking 
the  sap  from  leaves  and  veins  of  cabbage  and  other  crucifers, 
the  aiTected  leaves  wilting,  withering  and  dying  as  if  fire- 
swept — whence  the  name  "fire  bug."  Half  a  dozen  mature 
insects  suffice  to  destroy  a  small  plant  in  a  day.  This  is  a 
pest  which,  if  permitted  to  have  its  own  way.  is  almost  certain 
to  destroy  a  portion,  and  if  sufficiently  numerous,  all  of  the 
fields  which  it  infests,  and  the  writer  has  seen  in  the  vicinity  of 
the  District  of  Columbia,  in  Maryland  and  Virginia  many  fields 
in  successive  years  from  which  not  a  single  good  cabbage  could 
be  cut,  and  has  observed  equal  injury  to  horseradish  and  some 
other  crucifers.  Toward  the  end  of  the  season  and  in  early 
winter  the  mature  bugs  are  still  afield,  seeming  loath  to  seek 
shelter  from  the  cold.  When  cruciferous  crops  have  become 
exhausted  they  attack  almost  any  form  of  vegetation. 

Preventive  and  Remedial  Measures. — The  difficulty  of  de- 
stroying this  insect  with  contact  poisons  such  as  kerosene- 
soap  emulsion,  which  are  practically  inert  against  the  adults 
and  only  partially  effective  on  the  youngest  nymphs,  necessi- 
tates the  Use  of  preventives  to  compass  this  end.  The  most 
important  is  clean  farm  practice.  The  practice  of  leaving 
cabbage  stalks  and  other  cruciferous  plants  in  the  field  late  in 
autumn  and  early  winter,  or  of  allowing  cruciferous  weeds  to 
grow  up,  or,  in  fact,  allowing  any  sort  of  debris  to  accumulate, 
serves  to  protract  the  life  of  this  insect  by  affording  it  food 
or  quarters  for  protection  against  the  cold.  It  is  inadvisable 
to  plant  crucifers  in  the  vicinity  of  outhouses  and  barns,  as 
the  bugs  use  such  places  for  passing  the  winter. 

Some  of  the  insect's  food  plants  may  be  left,  after  cropping, 
at  intervals  throughout  fields  to  attract  the  bugs  in  the  fall, 
and  here  they  may  be  killed  with  crude  kerosene,  by  mechanical 


150  INSECTS    INJURIOUS    TO    VEGETABLES 

methods,  or  piles  of  rubbish  may  be  left  to  attract  them  where 
they  can  be  burned. 

The  best  remedy,  however,  and  one  that  should  be  put  into 
operation  by  every  southern  cabbage  grower,  is  the  planting  of 
an  early  crop  of  mustard,  radish,  rape,  or  kale  as  a  lure  for 
the  first  appearing  bugs.  Overwintered  bugs  appear  from 
March  to  May.  Tliey  appear  to  prefer  for  the  first  deposition 
of  their  eggs  the  plants  that  have  been  mentioned,  though 
cabbage  may  be  available.  On  these  the  insects  are  killed  by 
kerosene  or  by  hand,  as,  for  example,  by  capture  with  a  hand 
net.  or  by  burning  the  traps   when  these   are   of   no  value  as 


Fig.   101.— False  chinch-bug.    a,  Leaf  showing  punctures;  b.  last  nymph  stage, 
c,  adult,    a.  Natural  size;  6,  c  much  enlarged.    (After  Riley) 

food.  If  the  first  generation  is  generally  done  away  with,  few 
insects  fly  from  other  quarters,  and  injury  is  largely  prevented 
for  an  entire  season. 

The  False  Chinch-bug  (Nysius  angustatiis  Uhl.). — The  false 
chinch-bug.  although  a  general  feeder,  appears  to  be  somewhat 
more  attached  to  turnip,  cabbage  and  similar  crops,  but  also 
injuriously  affects  potato,  beets,  lettuce,  the  vine,  apple,  grass 
and  strawberry.  It  derives  its  name  of  false  chinch-bug  from 
its  being  frequently  mistaken  for  the  true  chinch-bug,  to 
which  indeed  it  is  related.  The  adult  is  grayish  brown  and 
of  the  appearance  shown  in  figure  loi,  c.  The  hemelytra  or  wing- 
covers  are  more  or  less  transparent.  The  length  is  about 
one-eighth  of  an  inch.     In  distribution  it  extends  from  New 


INSECTS  INJURIOUS  TO  CABBAGE  AND  OTHER  CROPS      I5I 

Hampshire  to  the  Gulf,  and  westward  to  the  Pacific  States. 
At  o  of  figure  loi  is  represented  the  appearance  of  a  leaf 
of  potato  showing  the  minute,  rusty  circular  specks  where  the 
beak  of  this  bug  has  been  inserted.  The  false  chinch-bug 
frequently  occurs  in  such  number:^  as  to  attract  general  atten- 
tion. The  bugs  crowd  together  on  a  plant  in  the  same  manner 
as  do  the  chinch-bugs  on  corn,  and  the  harlequin  bugs  on 
cabbage;  and  as  they  also  feed  by  suction,  they  soon  exhaust  a 
plant  by  depriving  it  of  its  juices,  which  in  time  causes  it  to 
wilt  and  die.  This  is  an  active  bug,  and  when  alarmed  on 
warm  days,  the  winged  individuals  readily  take  to  flight,  arising 
in  swarms.  It  is  subject  to  the  same  atmospheric  influences 
as  the  chinch-bug,  and  damp,  rainy  weather  is  unfavorable  to 
its  development.  It  has  been  surmised  that  there  are  two  er 
three  generations  a  year  and  that  the  insect  hibernates  mainly 
in  the  perfect  state  under  rubbish  of  different  sorts. ^ 

Remedies.— The  best  way  of  controlling  this  bug  consists  in 
the  keeping  down  of  purslane,  a  favorite  food  plant,  the 
careful  cleaning  up  and  burning  of  all  trash  before  winter,  the 
collection  of  the  bugs  when  they  occur  in  numbers  in  pans  or 
pails  filled  with  water  and  a  thin  scum  of  kerosene,  and  the 
free  use  of  10  per  cent,  kerosene  emulsion. 

The  Cabbage  Aphis  {Aphis  hrassicce  Linn.). — In  seasons  when 
atmospheric  conditions  favor  its  development  this  insect,  which 
is  also  known  as  the  "cabbage  louse","  can  be  exceedingly 
troublesome;  indeed,  were  it  not  for  its  susceptibility  to  many 
natural  enemies,  it  would  always  be  a  pest  of  the  highest  im- 
portance in  localities  adapted  for  its  increase.  This  species 
afifords  a  most  excellent  example  of  the  usefulness  of  natural 
enemies.      A    vast    number    of    insects    that    prey    on    aphides 

1  A  related  bug  (Nysius  minntus  Uhl.)  very  nearly  resembles  the  preceding 
in  appearance  and  in  habits,  and  may  be  controlled  by  the  same  methods. 

8  A  similar  aphis  (Rhopalosiphum  dianthi  Schr.),  with  somewhat  similar  habits, 
is  also  very  injurious  to  cole  crops  and  may  be  controlled  by  about  the  same 
means. 


152 


INSECTS    INJURIOUS   TO   VEGETABLES 


attack  it,  and  in  many  regions  hold  it  down  to  moderate  num- 
bers save  in  exceptional  seasons.  In  dry,  warm  weather  the 
insect  enemies  are  most  active,  while  in  cooler  dry  weather 
they  are  less  efficient  and  then  the  plant-lice  frequently  gain 
the  ascendency,  to  the  detriment  of  the  cabbage  crop. 

Its  first  appearance  is  usually  noticed  in  June,  and  it  remains 


Fig  102.— Cabbage  aphis,  a,  So-called  "  male  "  ;  b,  wingless  viviparous  female.    Greatly 
enlarged;  natural  size  indicated  by  small  outlines.    (After  Curtis) 

until  quite  cold  weather.  In  the  District  of  Columbia  the  writer 
has  observed  this  species  active  as  late  as  the  middle  of  Decem- 
ber, mostly,  however,  at  this  time,  in  the  hearts  of  cabbage, 
where  the  aphides  had  crawled  for  protection. 

Practically  the  same  or  related  insect  enemies  of  the  pea 
aphis  which  have  been  mentioned  in  preceding  pages  attack 
the  cabbage  aphis. 

Remedies. — The  cabbage  aphis  can  be  controlled  by  much  the 
same  remedies  as  advised  for  the  melon  aphis  (page  165),  the 
free  use  of  pyrethrum  applied  by  a  bellows  at  any  stage  of  the 
growth  of  the  cabbage  or  other  plant ;  or  by  kerosene  emulsion, 
which  is  of  value  when  the  plants  are  young  and  until  the 
heads  begin  to  complete  their  growth.  Soap  solutions  may  be 
used  if  preferred,  those  known  as  whale-oil  soap,  made  of  fish 
oil,  and  potash  soaps,  made  from  caustic  potash,  being  the  best. 
A  strong  stream  of   water  directed  upon  the  plants   from  a 


INSECTS  INJURIOUS  TO  CABBAGE  AND  OTHER  CROPS      I53 

syringe,  hose  or  spraying  machine  is  often  of  service  in  check- 
ing the  work  of  this  insect.  Application  of  remedies  should 
be  made  upon  the  first  appearance  of  the  insects.  Clean  cultural 
practice  should  be  observed. 

MAGGOT   LEAF-MINERS 

The  leaves  of  cabbage,  turnip,  radish  and  other  crucifers 
are  subject  to  the  attack  of  minute  maggots  which  manifest 
their   presence   by    whitish   blotches   of    larger   or    less    extent, 


Fig.  103.— Imported  turnip  leaf-miner,  a.  Larva;  b,  puparium;  c,  adult;  d,  antenna  of  fly; 
e,  work  in  radish  leaf.  Natural  size;  all.  others  enlarged.  (Reengraved  after  Coquil- 
lett.  U.  S.  Dept.  Agr.) 


termed  mines.  If  a  leaf  be  held  toward  the  light  the  maggot 
can  be  seen  at  work  between  the  surfaces.  Four  species  of 
leaf-miners  commonly  affect  crucifers.  These  insects  are  not 
as  a  rule  very  destructive,  but  they  kill  off  leaves  here  and 
there,  thus  weakening  the  plants,  and  rendering  them  more 
liable  to  disease  and  to  injury  by  other  insects.  Sometimes, 
however,  they  destroy  whole  plants.  Attack  is  more  apparent 
on  young  plants  and  is  easily  recognized.    One  of  the  commonest 


154  INSECTS    INJURIOUS   TO   VEGETABLES 

of  these  insects  is  the  imported  turnip  leaf-miner  (Scaptomyza 
flaveola  Meig.)  shown  in  figure  103. 

Remedies. — These  leaf-miners  are  not  very  injurious  to  large 
interests.  In  small  gardens  they  can  be  controlled  by  clipping 
the  infested  leaves  as  soon  as  the  mines  appear  and  destroying 
them. 


Fig.  103x.— A  young  cabbage  looper,  highly  magnified.    (Author,  U-  S.  D«pt.  Agr.; 


CHAPTER    X 

INSECTS   INJURIOUS   TO    CUCUMBER,    MELON 
AND  RELATED  PLANTS 

If  we  except  cabbage  no  vegetable  crops  suffer  more  from 
the  ravages  of  insects  than  do  the  cucurbits — squashes,  cucum- 
bers and  melons.  They  are  subject  to  attack  from  the  time 
the  seed  is  planted  and  after  it  has  sprouted  until  the  fruit 
is  ripe  for  market.  Injury  is  not  effected  by  so  many  species 
of  insects,  as  in  the  case  of  cabbage,  less  than  a  score  of 
distinct  forms  being  commonly  identified  with  damage,  but  of 
these  nearly  a  dozen  are  highly  injurious,  and  half  as  many 
from  their  extensive  distribution  and  destructiveness  are  of 
the  greatest  importance.  It  is  no  uncommon  sight  to  see  four 
or  five  distinct  species  on  a  single  plant,  and  several  others  in 
the  same  field. 

The  seeds  are  attacked  in  the  ground  by  a  maggot  which  eats 
into  them  and  prevents  germination.  After  the  seed  has 
sprouted  the  plant  becomes  the  prey  of  the  striped  cucumber 
beetle,  the  most  troublesome  of  all  cucurbit-feeding  insects. 
Such  plants  as  are  so  fortunate  as  not  to  be  attacked  by  this 
beetle,  cutworms  and  some  few  other  "general  feeders"  may 
next  encounter  the  squash  bug  and  then  the  squash-vine 
borer.  The  latter  severs  the  vine  or  injures  it  so  that  it  wilts  and 
dies.  It  is  next  to  impossible  in  many  portions  of  the  United 
States  to  find  cucurbits  that  are  wholly  free  from  the  melon 
aphis  which  feeds  by  absorbing  vegetable  juices  by  suction. 
After  the  plants  have  escaped  the  insects   above  enumerated 

155 


156 


INSECTS    INJURIOUS   TO    VEGETABLES 


they  are  still  liable  to  injury  from  others  and  more  especially 
from  the  pickle  worm  and  melon  caterpillar  which  bore  into  the 
fruit  and  render  it  unfit  for  market. 

Cucurbits  grown  under  glass  are  subject  to  injury  by  four 
important  pests :  the  striped  cucumber  beetle,  melon  aphis, 
greenhouse  white  fly  and  onion  thrips. 

The  Striped  Cucumber  Beetle  (Diabrotica  vittata  Fab.). — 
With  the  first  appearance  of  cucumber,  squash  and  melon  plants 


Fig. 


104.— Striped  cucumber  beetle,  a,  Beetle;  b,  larva;  c,  pupa;  d,  egg;  e,  sculp- 
ture of  egg.    (Author's  Illustration,  U.  S.  Dept.  Agr.) 


early  in  the  season,  often  before  they  are  above  ground,  they 
are  attacked  by  the  striped  cucumber  beetle,  often  called  the 
"striped  bug"  and  "melon  bug." 

The  beetle  measures  about  two-fifths  of  an  inch  in  length. 
Its  color  is  yellow  above,  with  black  head  and  elytra  longi- 
tudinally striped,  as  figured  (fig.  104).  The  egg  is  lemon  yel- 
low and  of  the  appearance  shown,  where  the  sculpture  is  also 
illustrated.  The  larva  is  a  slender,  white,  worm-like  creature, 
with  brown  head,  anal  and  thoracic  plate.  When  mature 
it  measures  about  three-tenths  of  an  inch,  this  being  about 
ten  times  its  width.  The  species  is  indigenous  and  inhabits  the 
entire  eastern  United  States. 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         1 57 

The  principal  injury  is  effected  by  the  hibernated  beetles 
devouring  the  tender  plants  before  they  have  fairly  started. 
The  beetles  are  also  destructive  to  older  plants,  by  eating  the 
leaves  and  gnawing  the  rind  of  stems  and  the  fruit,  while  the 
larvae  cause  injury  through  their  pernicious  work  at  the  roots. 
Still  another  form  of  mischief  is  due  to  the  beetles  in  acting 
as  carriers  of  the  insidious  bacterial  disease  "cucurbit  wilt." 

The  beetles  usually  make  their  appearance  in  April  or  May, 
feed  on  flowers  or  other  vegetation,  and  when  cucurbits  are  set 
out  attack  and  injure  them  as  previously  described.  Eggs  are 
deposited  soon,  after  the  host 
plants  are  well  above  ground, 
and  on  leaf-stalks  just  below  the 
surface  of  the  ground.  The 
larval  period  is  passed  in  the 
earth,  about  the  bases  of  the 
stalks,  and  larvae  may  be  found 
within  the  stems  under  as  well 
as  above  ground,  and  there 
is  an  active  stage  of  about  a 
month's  duration  in  which  the 
larvae  working  in  numbers  have  F'g-  \05.-Celatoria  diabrotwx.  Fiypara- 

,  .  p  .     .       .  ,  site  of  cucumber  beetles.   Much  enlarged, 

ample  trnie  for  injuring  the  (Author's  illustration,  U.  S.  Dept.  Agr.) 
vines. 

Toward  the  end  of  the  season  the  beetles  congregate  under 
stems,  prostrate  plants  and  withered  leaves  of  cucurbits,  as 
many  as  sixty  individuals  assembling  about  a  single  plant,  and 
later  they* seek  other  places  of  shelter.  "  Hibernation  near 
Washington  evidently  begins  during  the  first  cold  nights  of 
October. 

Great  numbers  of  this  insect  are  destroyed  by  a  dipterous 
parasite,  somewhat  resembling  a  small  house  fly,  and  known 
as  Celatoria  diabrotica;  Shim.  (fig.  105),  which  develops  as  a 
maggot  within  the  beetle,  which  it  destroys  when  it  issues. 


1S8  INSECTS    INJURIOUS    TO   VEGETABLES 

REMEDIES 

How  to  control  this  cucumber  beetle  is  one  of  the  hardest 
propositions  to  solve.  Poisons  will  destroy  the  beetles  when  they 
occur  in  moderate  numbers,  but  are  not  entirely  efficacious 
when  they  are  most  abundant,  hence  recourse  must  be  had  to 
preventives  and  repellents,  and  to  farm  practice. 

Coverings. — To  prevent  injury  to  young  plants  coverings  are 
used.  A  cheap  frame  may  be  made  by  cutting  a  barrel  hoop  in 
two  so  as  to  form  two  semicircles,  which  are  placed  at  right 
angles  to  each  other,  and  the  lower  ends  inserted  in  the  ground 
with  the  curve  uppermost.  This  is  then  covered  with  gauze  or 
similar  material,  held  in  place  so  to  prevent  the  beetles  work- 
ing through  or  under  it. 

Early  planting,  etc. — Where  no  covering  is  used  it  is  advisable 
to  start  plants  under  glass,  or  to  plant  the  earliest  varieties  and 
set  them  out  as  soon  as  possible  so  as  to  have  the  plant  well 
established  before  the  appearance  of  the  beetles.  The  setting 
out  of  late  varieties  should  be  postponed  until  after  the  first 
appearing  beetles  have  laid  their  eggs  and  dispersed.  A  cer- 
tain degree  of  relief  follows  the  planting  of  an  excess  of  seed 
so  as  to  distribute  attack.  After  the  first  danger  is  passed  the 
hills  are  thinned  out  to  the  desired  number. 

Clean  farming  and  trap  plants. — Much  injury  from  this  and 
other  cucurbit  pests  would  be  prevented  by  more  attention  to 
clean  methods  of  cultivation.  As  soon  as  a  crop  is  harvested 
the  vines  should  be  covered  with  straw  or  other  inflammable 
material  and  burned,  and  certain  plants  should  be  left  here 
and  there  throughout  the  fields,  so  that  such  insects  as  may  not 
be  reached  by  the  fire  will  concentrate  on  them  where  they  can 
be  destroyed  with  strong  kerosene  emulsion  or  Paris  green. 
As  traps  for  the  last  generation  it  would  be  wise  to  plant  late" 
or  to  use  later  varieties.  Some  exemption  may  be  attained  by 
growing  beans  with  cucumbers  in  alternate  rows.  The  beans 
are  planted  before  the  cucumbers  and  the  beetles  congregate 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         1 59 

on  the  beans  and,  having  an  abundance  of  food,  do  not  attack 
the  young  cucurbits. 

Driving,  etc. — In  some  sections  "driving"  is  practiced.  Air- 
slaked  lime  is  dusted  over  the  plants  with  the  wind  and  the 
beetles  fly  before  it  to  the  next  patch  where  similar  methods 
have  to  be  employed.  Another  remedy  is  to  dust  the  majority 
of  plants  with  sifted  ashes,  road  dust  or  plaster,  and  cover 
those  which  are  undusted  with  an  arsenical,  in  the  proportion  of 
one-fourth  of  a  pound  to  about  40  gallons  of  water.  The 
beetles  are  thus  driven  to  concentrate  on  the  clean  plants,  where 
they  are  killed  by  the  poison. 

Refuse  tobacco  dust  sprinkled  on  the  hills  when  the  soil  is 
moist  acts  as  a  repellent  and  as  a  fertilizer  and  mulch  for  the 
plant.    Applications  must  be  renewed  when  rainfall  necessitates. 

Pyrethrum  and  other  insecticides  dusted  on  the  plants  are 
useful,  but  expensive.  Paris  green  and  other  arsenicals  applied 
dry  as  for  potato  beetles  are  valuable,  but  all  poisons  must  be 
renewed  frequently  and  are  not  generally  to  be  relied  upon 
when  the  beetles  are  exceedingly  numerous.  In  case  Bordeaux 
mixture  is  used  as  a  protection  against  fungous  diseases,  Paris 
green  should  be  added,  as  it  necessitates  little  additional  trouble 
and  the  mixture  will  prove  more  effective  than  either  when 
used  alone. 

Stimulating  growth. — A  considerable  degree  of  exemption 
from  injury  accrues  from  the  stimulation  of  a  crop  by  heavy 
manuring,  or  the  use  of  mineral  fertilizers  and  frequent 
cultivation. 

The  Twelve-spotted  Cucumber  Beetle  (Diabrotica  12-punctata 
01.). — This  beetle  will  be  considered  at  length  in  the  dis- 
cussion of  insects  affecting  sweet  corn.  In  exceptional  sea- 
sons it  does  nearly  as  much  injury  locally  to  cucurbits  as  the 
striped  cucumber  beetle,  with  which  it  is  nearly  always  asso- 
ciated.    At  such  times,  the  same  remedies  should  be  employed. 


i6o 


INSECTS    INJURIOUS    TO   VEGETABLES 


The  Squash  Ladybird  (Epilachna  borealis  Fab.)- — The 
leaves  of  squash,  pumpkin  and  the  other  cucurbits  are  often 
found  showing  numerous  wilted  and  eroded  circular  or  semi- 
circular spaces.  The  source  is  not  far  to  seek,  and  can  readily 
be  traced  to  the  squash  ladybird  and  its  larva.  This  insect  is 
of  the  characteristic  hemispherical  ladybird  form.  It  is  ochra- 
ceous  in  color,  marked  with  rounded  black  spots,  as  shown  in 
figure  1 06,  c.  This  is  one  of  our  largest  ladybirds,  measuring 
about  one-third  of  an  inch.     The  larva  is  yellow  and  covered 


a  h 

Fig.  106.- Squash  ladybird,  a.  Larva;  b.  pupa;  c,  beetle;  rf,  egg;  e.  surface  of  same. 
a,  b,  c.  Three  times  natural  size;  d,  four  times;  e,  highly  magnified.  (Author's  illus- 
tration, U.  S.  Dept.  Agr.) 

with  spines  arranged  in  six  rows  except  on  the  first  thoracic 
segment,  where  there  are  four  (a). 

This  is  an  indigene,  ranging  from  South  America  to  Maine 
and  Canada.  It  is  essentially  an  eastern  form,  occurring 
abundantly  along  the  Atlantic  seaboard. 

The  singular  habit  of  the  larva  and  beetle  of  feeding  within 
a  circumscribed  space,  as  previously  noted,  is  evidently  char- 
acteristic of  this  genus  of  ladybirds.  It  first  marks  out  a 
circle,  or  if  it  is  feeding  on  the  edge  of  a  leaf  a  more  or  less 
complete  semicircle,  thus  enclosing  a  portion  within  which  it 
feeds.  The  larva  lives  on  the  lower  and  the  beetles  on  the 
upper  surface,  but  the  latter  may  often  be  found  on  the  under 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         l6l 

side,  and  devour  all  parts  except  the  veins  and  late  in  the 
season  sometimes  eat  the  rind  of  the  fruit.  The  beetle  hiber- 
nates under  convenient  shelter  and  appears  abroad  in  May  or 
June  according  to  season  and  locality.  A  single  generation 
has  been  observed. 

Remedies. — Remedial  measures  adopted  for  other  cucurbit 
pests  will  effect  the  destruction  of  this  ladybird.  Its  habit  of 
feeding  exposed  on  the  leaves  renders  it  vulnerable  to  poison- 
ous applications,  and  of  these  the  arsenites,  dry  or  in  solution, 
are  best.  Hand-picking  the  beetles  and  egg  masses  is  the  only 
measure  necessary  under  usual  circumstances. 


Fig. 


1 07.— Work  of  squash  ladybird  on  a  squash  leaf.     Natural  size 
(Author's  illustration,  U  S  Dept.  Agr.) 


The  Sciuash  Bug  {Anasa  frisfis  DeG.).— Of  all  insects  which 
infest  squash  and  pumpkin  the  squash  bug  is  the  best  known. 
It  is  also  called  "stink-bug"  from  its  disagreeable  odor,  and 
black  or  gray  squash  bug  to  distinguish  it  from  the  so-called 
"striped  bug."  In  some  seasons  as,  for  example,  in  1901  and 
1902,  it  even  vies  with  the  latter  in  point  of  destructiveness. 

The  adult  bug,  shown  twice  natural  size  in  figure  108,  c,  is 
nearly  three-fourths  of  an  inch  long,  dirty  blackish  brown  above 
and  mottled  yellowish  beneath.  It  is  more  or  less  harmful 
during  its  entire  active  existence,  from  the  time  it  leaves  the 
egg  till  its  demise.     When  numbers  attack  a  plant  together  it 


1 62 


INSECTS    INJURIOUS   TO   VEGETABLES 


is  soon  exhausted,  the  tips  and  leaves  wilt  and  its  death  fol- 
lows. It  is  not  alone  the  extraction  of  the  juices  that  destroys 
a  plant;,  whenever  the  bug  "stings"  a  leaf-stalk,  it  injects  a 
liquid,  which  has  a  poisonous  effect,  causing  the  death  of  the 
cell  tissue  about  the  puncture.  It  attacks  also  the  leaves  and 
occasionally  the  fruit,  and  acts  as  a  transmitter  of  the  "wilt." 


d  e 

Fig.  108.— Squash  bug.    a.  Adult;  b,  egg  mass;  c,  d,  e,  nymphal  stages.    Enlarged 
(Author's  illustration,  U.S.  Dept.  Agr.) 


On  young  plants  a  few  punctures  are  sometimes  sufficient 
to  cause  death. 

The  common  squash  bug  is  known  throughout  practically 
the  entire  United  States,  being  particularly  abundant  east  of 
the  Rocky  Mountains,  where  it  ranges  from  Maine  to  the 
Gulf  States  and  westward  to  California. 

Injury  may  begin  soon  after  the  sprouting  of  the  plants,  or 
after  they  have  made  considerable  growth,  and  may  continue 
until  their  death  or  the  departure  of  the  bugs  for  hibernation. 
Plants  are  first  attacked  by  the  hibernated  bugs.  Soon  after 
their  appearance,  which  varies  according  to  temperature  and 
locality  from  early  spring  in  the  South  to  late  in  June  farther 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         163 

north,  the  insects  deposit  their  eggs,  attaching  them  by  an  ad- 
hesive secretion  to  the  leaves  in  masses  of  three  or  four  to 
forty  or  more.  The  eggs  are  metallic  brown  or  bronze  and 
flattened  on  three  sides.  They  are  laid  usually  on  the  under 
side  of  a  leaf,  but  not  infrequently  on  the  upper  side,  in  more 
or  less  regular  rows  (fig.  108,  b).  They  hatch  in  from  eight 
to  thirteen  days  into  small,  green  and  black  creatures,  which 
resemble  somewhat  the  mature  insects,  having  proportionately 
longer  legs  and  antennae.  In  this  period  of  its  existence,  the 
first  nymph  stage  (fig.  108,  c),  the  insect  lives  in  colonies,  at 


Fig.  \09.—Trichopoda  pennipes.    Tachina  fly  parasite.    Three  times  natural  size 
(Author's  illustration,  U.  S-  Dept.  Agr.) 

first  remaining  close  together  upon  the  leaf  near  where  the 
eggs  were  laid,  but  later  congregating  about  the  bases  of  leaf- 
stalks or  hiding,  together  with  individuals  of  the  more  ad- 
vanced stages,  under  clods  or  rubbish  or  in  any  convenient 
retreat,  and  coming  forth  toward  dusk  in  search  of  food.  The 
nymphs  cast  their  skins  five  times  before  reaching  the  mature 
condition,  increasing  their  growth  with  each  molt.  In  its  last 
stage  the  squash  bug  continues  to  feed,  but  with  the  disappear- 
ance of  its  food  supply,  caused  by  the  dying  or  clearing  away  of 
the  crop  on  which  it  has  fed,  it  seeks  shelter  in  any  convenient 
rubbish,   under   boards   or    stones,   dead   vegetation,    or   under 


164  INSECTS    INJURIOUS   TO   VEGETABLES 

bark,  or  in  cracks  of  barns,  and  here  passes  the  winter.  Hiber- 
nation in  the  District  of  Columbia  begins  sometime  In  Sep- 
tember. 

This  bug  is  often  parasitized  by  a  tachina  fly  which  assists 
in  holding  down  its  numbers.  It  is  Trichopoda  pennipes,  shown 
in  figure   109. 

Methods  of  Control. — This  insect  is  unusually  resistant  to 
insecticides.  A  wash  strong  enough  to  kill  the  mature  insect 
will  destroy  the  vines.  This  renders  it  necessary  to  proceed 
by  hand  and  cultural  methods. 

A  lookout  for  the  bugs  should  be  kept  early  in  the  season 
and  these  as  well  as  the  eggs  should  be  picked  off  or  cut 
away  and  destroyed.  The  eggs  are  readily  seen,  and  the 
grower  should  make  a  practice  at  the  beginning  of  each  sea- 
son of  going  over  the  vines  every  few  days.  Such  young  as 
hatch  in  spite  of  these  precautions  may  be  killed  by  kerosene 
emulsion  if  applied  at  their  first  appearance. 

The  bugs  may  be  trapped  by  placing  about  the  garden  boards, 
shingles,  or  similar  material,  which  will  attract  them  for  shelter. 
Here  they  should  be  destroyed  every  morning  or  so  during  the 
early  season.  Protection  to  cucurbits  other  than  squash,  and 
perhaps  pumpkin,  can  be  facilitated  by  growing  these  plants 
with  others  to  serve  as  trap  crops.  Attack  will  thus  be  cen- 
tered on  a  few  plants  where  the  insects  can  be  the  more 
readily  controlled. 

A  number  of  the  remedies  in  use  against  the  striped  cucumber 
beetle  and  other  insect  enemies  of  cucurbits  will  assist  in  the 
control  of  this  species.  Among  these  are  the  protection  of 
young  plants  with  coverings,  the  use  of  repellents,  planting  an 
excess  of  seed  to  distribute  attack,  stimulating  the  plant  by 
manures  or  other  proper  fertilizer,  and  lastly,  clean  cultural 
practice.  If  the  vines  as  soon  as  the  crop  is  harvested  are 
gathered  and  burned,  many  bugs  will  be  destroyed  and  the 
number  reduced  for  the  ensuing  year. 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON^  ETC,         165 

The  Melon  Aphis  (Aphis  gossypii  Glov.). — The  melon  aphis 
or  "louse"  may  serve  as  typical  of  the  plant-lice.  It  is  in  some 
seasons  one  of  the  most  important  enemies  of  melons  and  some 
other  crops,  and  is  injurious  like  other  aphides  by  piercing 
the  plants  affected  with  its  beak  and  thus  sapping  their  vitality. 
It  occurs  from  early  spring  to  late  in  autumn  on  cucurbits  of 
all  kinds,  many  other  crops  and  weeds  of  great  variety  and 
in  its  seasons  of  abundance,  notably  following  springs  that 
are  cool  and  rainy,  it  frequently  does  very  serious  damage, 
causing  the  leaves  attacked  to  curl,  shrivel  and  lose  color,  inter- 
fering with  the  ultimate  development  of  the  fruit,  if  not  kill- 
ing the  plants  outright. 

The  melon  aphis  is  variable  dark  green  in  color  and  of 
sluggish  habit. ^  The  principal  stages  are  illustrated  in 
figure  47.  Winter  eggs  have  been  found  on  strawberry  and 
purslane.  This  species  is  of  unknown  but  perhaps  tropical 
origin,  since  it  shows  a  decided  preference  for,  and  has  done 
most  injury  to,  plants  of  a  tropical  nature,  such  as  cucurbits, 
cotton  and  orange. 

METHODS    OF    CONTROL 

The  severe  losses  occasioned  by  this  insect  in  seasons  when 
it  multiplies  in  unusual  numbers  could  be  largely  mitigated 
and,  in  small  areas,  almost  entirely  prevented  if  the  employ- 
ment of  methods  of  destruction  were  begun  upon  its  first  ap- 
pearance. First  of  all,  it  is  necessary  to  familiarize  oneself  with 
the  insect  and  the  condition  of  the  plants  by  which  its  pres- 
ence is  manifest  that  measures  of  control  may  be  instituted 
before  it  is  too  late.  In  ordinary  seasons  it  is  controlled  by 
natural  elements  and  insect  enemies  alone,  and  when  the 
weather  is  unfavorable  to  the  development  of  the  latter  the 
grower  should  be  on  the  alert. 

1  The  only  other  cucurbit  louse  with  w-hich  it  is  apt  to  be  confused  is  the 
squash  aphis  {Nectarophora  cttcurbitce  Middleton),  a  much  larger  species  and 
more   uniformly  paler  green  in   color. 


i66 


INSECTS   INJURIOUS   TO   VEGETABLES 


Fig.  110. — Cantaloupe  leaves  showing  curling  caused  by  melon  aphis;  aphides  on  lower 
surface.    Slightiy  reduced.    (Author's  illustration,  U-  S.  Dept.  Agr.) 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         167 

Bisulphid  of  carbon. — In  small  fields  it  is  customary  to  cover 
hills  of  melons  as  soon  as  the  insects  make  their  appearance 
with  a  tub  or  similar  receptacle,  and  evaporate  beneath  this 
bisulphid  of  carbon  at  the  rate  of  a  drachm  to  a  cubic  foot  or 
less  of  space.  A  tablespoonful  serves  for  ordinary  tubs.  This 
does  not  injure  the  plant,  and  if  the  tub  fits  tightly  to  the 
ground  so  as  to  retain  the  vapor  of  the  bisulphid,  the  "lice  '  will 
all  be  killed.  Large  growers  watch  vines  carefully,  removing 
and  destroying  affected  plants  as  soon  as  noticed  to  prevent 
spreading  the  trouble. 

Kerosene  emulsion  and  soap  solutions. — The  melon  aphis 
could  be  more  readily  dealt  with  if  it  did  not  feed  on  the 
under  surface  of  leaves,  and  if  vines  like  melons  did  not 
grow  so  closely  together  as  to  interlace  that  spraying  by 
ordinary  means  is  practically  impossible.  Under-spraying  is  a 
necessity,  and  the  sprayer  used  should  be  fitted  with  an  up- 
turned nozzle  to  secure  this  effect. 

Soap  solutions,  such  as  whale-oil,  fish-oil  and  potash  soap, 
are  not  so  useful. 

Clean  farming  zvith  fall  plozving  should  always  be  followed, 
as  it  is  a  most  valuable  measure  of  prevention  of  attack  by 
aphides  and  other  insects  that  are  present.  As  soon  as  the  crop 
is  off  remnants  should  be  gathered  and  burned,  and  all  weeds 
kept  down  until  the  fields  are  again  planted,  since,  as  has  been 
shown,  common  weeds  of  the  field  and  garden  serve  as  alter- 
nate food  plants,  and  are  selected  as  hibernating  quarters  by  the 
"lice." 

Pyrethrum  applied  to  the  underside  of  the  leaves  with  a 
powder  bellows  is  effective,  but  can  not  be  used  with  profit  on 
large  fields  or  on  plants  like  squash  with  large  leaves. 

Remedies  that  have  been  indicated  as  of  service  in  the  con- 
trol of  the  melon  aphis  operate  against  many  other  insects 
which  are  usually  present  at  the  same  time.  Thus  the  kero- 
sene  and   soap   solutions   kill    small    squash   bugs   and   act   as 


i68 


INSECTS    INJURIOUS   TO    VEGETABLES 


deterrents  of  other  insects,  bisulphid  of  carbon  destroys  other 
aphides  and  small  bugs,  as  does  also  pyrethrum.' 

The  Squash-vine  Borer  (Mclittia  satyrinifonnis  Hbn.).— A 
most  troublesome  enemy  of  squash,  pumpkin  and  other  cucur- 
bits is  the  squash-vine  borer.  In  many  localities  it  surpasses 
all  other  squash  insects  in  point  of  injuriousness.  Damage  is 
due  to  the  white  grub-like  larvcT  boring  through  the  stems, 
causing  them  to  rot  at  the  affected  points  and  become  severed 
from  the  vine.  The  presence  of  the  borer  in  the  stem  is  not 
apparent  at  the  commencement  of  the  attack,  but  soon  becomes 
manifest  through  the  presence  of  the  yellowish  powdery  excre- 


Fig.  1 1 1  .—Squash-vine  borer,  a,  Male  moth;  b,  female,  with  wings  folded  in  natural 
position  when  at  rest;  c,  eggs  shown  on  bit  of  squash  stem;  d,  full-grown  larva,  in  situ 
in  vine;  e.  pupa;  /,  pupal  cell.  All  one-third  larger  than  natural  size.  (Author's  illus- 
tration, U.  S.  Dept  Agr.) 

ment  which  it  forces  from  its  burrow  in  the  stem  and  which 
accumulates  on  the  ground  beneath,  as  well  as  by  the  sudden 
wilting  and  dying  down  of  the  leaves.  From  one  to  upwards 
of  145  individuals  have  been  reported  taken  from  a  single  plant. 
The  larvae  work  with  great  rapidity  and  in  a  short  time   in- 

'  A  detailed  account  of  the  melon  aphis,  Circ.  80,  Bu.  Entom.,  U.  S.  Dept. 
Agr.,  should  be  consulted  for  a  full  consideration  of  remedies. 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC. 


169 


jure  a  plant  so  that  no  fruit  will  mature.  Injury  is  most  notice- 
able near  the  bases  of  the  stems,  where  in  course  of  time  the 
vine  becomes  severed  from  the  roots. 

The  parent  insect  (fig.  iii,  a)  is  a  beautiful  clear-winged 
moth.  The  fore-wings  are  lustrous  olive-brown,  with  metallic 
green  reflections,  and  expand  about  an  inch  and  a  fourth.    The 


Fig.  1 12.— Squash- vine  borer,  a,  Egg  as  seen  from  above;  b,  same  from  the  side 
showing  sculpture;  c,  sculpture  of  egg  greatly  enlarged;  d,  newly-hatched  larva;  e, 
half-grown  larva;  /,  head  of  same  from  side;  g,  head  of  mature  larva  from  above,  a,  b 
and  rf,  Much  enlarged;  e.  fandg,  less  enlarged.    (Author's  illustration,  U.  S.  Dept.  Agr.) 


abdomen  is  marked  with  orange  or  red,  black  and  bronze,  and 
the  hind-legs  are  fringed  with  long  hairs. 

The  larva  is  soft,  whitish  and  grub-like.  Mature  larvse 
measure  about  an  inch.  In  the  District  of  Columbia  full-grown 
larvse  occur  as  early  as  the  middle  of  July  and  as  late  as  the 
second  week  of  November.  After  attaining  maturity  the 
larvse  enter  the  earth  to  the  depth  of  one  or  two  inches  and 
form  cocoons  (fig.  iii,  /)  constructed  of  silk  and  coated  ex- 
ternally with  fine  particles  of  earth.  Observations  indicate 
that  this  species  is  practically  single-brooded  northward;  that 
there  is  a  tendency  to  two  broods  in  New  Jersey;  that  in  the 
District  of  Columbia  the  species  is  partially  double-brooded, 
and  that  in  the  Gulf  States  it  is  fully  two-brooded. 


I/O  INSECTS   INJURIOUS   TO   VEGETABLES 

PREVENTIVE     AND     REMEDIAL     MEASURES 

This  borer  is  exceptionally  difficult  of  control,  as  ordinary 
insecticides  are  of  no  value  after  the  insect  has  entered  the 
vines,  and  repellents  are  also  practically  useless.  We  are,  there- 
fore, dependent  upon  cultural  methods  for  relief.  Knowing 
that  the  insect  passes  the  winter  in  the  fields  which  it  has 
ravaged,  it  should  be  superfluous  to  caution  growers  not  to 
plant  squashes  in  the  same  ground  in  successive  years. 

Early  squashes  as  traps. — Good  results  are  obtained  by  plant- 
ing as  early  as  possible  a  few  summer  squashes,  such  as  crook- 
neck  and  early  cymblin,  before,  and  between  rows  of,  the  main 
crop  of  late  varieties.  The  summer  squashes  attract  the  in- 
sects in  numbers,  leaving  a  smaller  number  to  deal  with  on 
the  main  crop.  As  soon  as  the  early  crop  is  gathered,  or 
earlier  if  the  ground  is  needed  for  the  main  crop,  the  vines  are 
raked  up  and  burned  to  destroy  all  eggs  and  larvae  which  they 
may  harbor,  and  the  same  treatment  is  followed  after  gathering 
the  late  varieties. 

Fall  harrozviiig  and  spring  plouing. — This  species  can  be 
greatly  reduced  by  lightly  harrowing  the  surface  of  infested 
squash  fields  in  the  fall  so  as  to  bring  the  cocoons  to  the 
surface,  where  they  will  be  exposed  to  the  elements,  and  then 
plowing  in  the  spring  to  a  uniform  depth  of  at  least  six  inches 
so  that  the  adults  will  not  be  able  to  issue. 

Cutting  out  the  borers,  although  laborious,  is  about  the  only 
method  open  for  employment  after  they  have  entered  the  vines. 
It  is  best  to  cut  longitudinally,  so  as  not  to  sever  the  vine 
from  the  root  stalk.  The  location  of  the  borer  in  the  vine  can 
be  detected  by  the  accumulation  of  its  yellow  excrement  at 
the  point  where  it  is  working. 

Other  methods. — When  vines  have  attained  some  length  parts 
of  them  should  be  covered  with  earth  so  that  secondary  roots 
will  be  sent  out  in  case  the  main  root  is  injured.    Keeping  plants 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         I7I 

in  good  condition,  free  from  disease  and  other  insects,  and  well 
nourished,  with  the  assistance  of  manure  or  other  fertilizer  if 
necessary,  will  also  aid  them  to  withstand  attack.  If  the 
grower  would  make  certain  of  securing  a  good  crop  in  localities 
where  this  and  other  enemies  of  the  squash  occur  in  their  most 
destructive  abundance,  it  will  be  necessary  for  protection  against 
this  borer  to  observe  most  of  the  precautions  specified  and,  if 
possible,  secure  the  cooperation  of  his  neighbors. 

The  Pickle  Worm  (Diaphauia  iiifidalis  Cram.). — In  the  Gulf 
States  and  occasionally  farther  northward  two  caterpillars  are 
quite  injurious  to  the  fruit  of  melons  and  other  cucurbits.  The 
term  "melon  worm"  is  applied  to  both,  as  also  to  the  squash 
borer,  since  all  have  the  habit  of  boring  into  melons;  the  last- 
mentioned,  however,  is  a  vine-borer,  while  the' other  two,  known 
respectively  as  the  pickle  worm  and  melon  caterpillar,  feed  in 
their  earlier  stages  in  the  buds  or  leaves,  and  in  their  later 
stages  in  the  fruits,  which  they  frequently  destroy.  They  are 
about  equally  destructive  and  work  usually  by  boring  directly 
into  the  interior,  but  sometimes  eat  cavities  in  the  rind. 

Injury  by  the  pickle  worm  is  seldom  noticed  until  it  enters 
the  fruit. 

The  moth  (fig.  113,  e)  is  a  beautiful  creature,  quite  distinct 
from  any  other  common  species.  The  upper  surface  is  brown 
with  purplish  iridescence.  Near  the  middle  of  the  fore-wings 
is  a  somewhat  irregular  yellowish  semitransparent  spot,  and 
the  inner  half  or  a  little  more  of  the  lower  wings  is  of  the 
same  color.  The  wing  expanse  varies  from  an  inch  to  nearly 
one  and  a  half  inches.  Larvae  (a,  h,  c)  vary  from  yellowish 
to  dull  brownish  green,  with  a  dorsal  row  of  shining  round 
spaces  of  the  same  color. 

The  pickle  worm  is  indigenous  to  America  and  is  probably  of 
tropical  origin.  It  occurs  from  South  America  to  New  York, 
Michigan  and  Illinois.  It  is  injurious  every  year  in  the  Gulf 
States,  instances  of  damage  farther  north  being  only  periodical. 


172 


INSECTS   INJURIOUS   TO   VEGETABLES 


Injury  appears  to  be  practically  clue  to  the  later-appearing  gen- 
erations, and  more  especially  to  muskmelons  raised  for  north- 
ern markets.  In  September,  1897,  fields  of  cymblins  cultivated 
in  Maryland,  Virginia  and  the  District  of  Columbia  were 
badly  damaged  or  totally  destroyed  by  the  pickle  worm,  but 
in  the  after  years  the  insect  has  almost  entirely  disappeared. 
The  life  history  and  habits  of  this  species  have  been  studied 


Fig.  1 1 3.— Pickle  worm,  a,  Larva;  b,  head  and  first  three  segments  of  larva;  c,  segment 
from  side;  d,  pickle  showing  injury;  e,  moth;  /,  cocoon,  a,  d,  e,  f.  Slightly  enlarged; 
b,  c,  more  enlarged.    (After  Riley.) 


by  Prof.  A.  L.  Quaintance,  in  Georgia.  Larvae  are  first  noticed 
there  about  the  middle  of  June.  Eggs  are  deposited  on  the 
flowers,  buds,  or  tender  portions  of  a  plant.  The  larvae  first 
eat  out  cavities  in  the  leaves  or  stems,  the  angle  between  a  leaf 
and  stem  being  a  favorite  place  of  entrance.  Frequently  they 
enter  flower  buds,  and  have  been  found  by  the  writer  destroying 
many  prospective  cymblins  in  this  manner.  With  the  second 
stage,  at  least  southward,  the  larvae  feed  on  the  young  fruit, 
and  as  they  mature  they  pass  from  plant  to  plant  and  thus 
injure  for  sale  much  of  the  fruit  affected.     They  void  large 


INSECTS  INJURIOUS  TO  CUCUMBER,   MELON,  ETC.         1 73 

quantities  of  soft  excrement  and  when  several  larvae  have  bored 
into  a  fruit  it  becomes  a  most  disgusting  object,  quite  different 
from  the  beautiful  moths  as  they  flit  about  the  garden.  The 
length  of  the  life  cycle  in  the  South  in  midsummer  is  between 
24  and  27  days  and  three  generations  seem  to  have  been 
definitely  recognized  there.  When  the  larvas  have  finished 
feeding  they  crawl  out  from  the  infested  fruit  and  transform  to 
pupae  within  the  fold  of  a  leaf  or  under  any  sort  of  debris  on 
the  ground. 

Methods  of  Control. — The  methods  that  have  been  ad- 
vised as  most  valuable  against  the  striped  cucumber  beetle  and 
other  species,  more  particularly  clean  farming,  fall  plowing 
and  rotation  of  crops,  are  useful,  but  the  pickle  worm  has 
never  been  successfully  combated.  The  writer  suggests  the 
combined  use  of  arsenate  of  lead  and  Paris  green,  spraying  with 
the  former,  at  the  rate  of  one  pound  to  from  15  to  25  gallons 
of  water,  beginning  at  about  the  time  that  the  buds  commence 
to  form,  and  making  a  second  application  a  week  or  two  later, 
according  to  how  well  the  arsenate  remains  on  the  foliage.  A 
third  spraying  may  be  made  if  necessary,  following  with  a  final 
3pray  of  Paris  green  (i  pound  to  130  gallons  water)  within 
about  a  week  of  the  time  of  the  ripening  of  the  fruit.  As  the 
arsenate  is  very  adhesive,  its  use  is  not  advised  for  the  final 
spraying.  The  Paris  green  which  is  substituted  at  this  stage 
is  perfectly  harmless,  as  it  readily  washes  ofif  if,  indeed,  any 
will  remain  by  the  time  the  fruit  is  placed  on  sale.  This 
treatment  is  designed  to  kill  the  "worms"  before  they  enter  the 
fruit,  since  they  cannot  be  reached  after  they  have  obtained 
entrance.  The  "worms"  are  poisoned  while  feeding  on  the 
buds,  leaves  and  other  parts,  as  well  as  on  the  rind  of  the 
fruit. 

The  Melon  Caterpillar  (Diaphania  hyalinata  Linn.). — This 
species  and  the  preceding  resemble  each  other  in  many  partic- 
ulars and  are  especially  alike  in  their  larval  stages,  but  there 


174 


INSECTS    INJURIOUS    TO    VEGETABLES 


is  this  difference,  important  to  the  grower,  that  the  first  genera- 
tion of  the  melon  caterpillar  usually  attacks  the  foliage,  partic- 
ularly of  muskmelon,  to  which  it.  as  well  as  the  preceding,  is 
most  destructive.     By  reason  of  this  habit  we  can  control  it,  in 


Fig. 


14.— Melon  caterpillar.    Moths,  larva  and  pupa  in  case.     Natural  size 
(From  Comstock) 


a  measure  at  least,  with  stomach  poisons,  which  is  impossible 
with  the  pickle  worm,  since  the  latter  lives  internally  through- 
out its  later  larval  stages. 

The  parent  insect  has  the  wings  pearly  white,  with  a  strong 
iridescence,  and  bordered  with  brown  (fig.  114).  The  cater- 
pillar when  full  grown  is  a  trifle  smaller  than  the  pickle  worm, 
measuring  about  eight-tenths  of  an  inch.  It  is  pale,  greenish 
yellow,  with  black  mouth-parts.     It  is  southern  in  distribution, 


INSECTS    INJURIOUS    TO    CUCUMBER,    MELON,    ETC.       175 


occurring  abundantly  in  the  Gulf  States.  The  "worms"  of 
these  two  species  are  frequently  confounded  because  of  their 
similar  appearance.  Both  feed  in  the  same  fields  and  their  life 
habits  exhibit  little  variation. 

Remedies  mentioned  for  the  pickle  worm  are  applicable,  as 
the  melon  caterpillar  can  be  killed  readily  by  an  arsenical  spray. 

Miscellaneous  Pests. — The  onion  thrips,  considered  on 
pages  89  and  90,  the  wheat  thrips  (page  90)  and  the  red  spider 
(page  91)  are  all  important  enemies  of 
cucumbers  grown  under  glass,  as  is  also 
the  greenhouse  white  fly  (Aleyrodes 
vaporarioriim  Westw.,  fig.  ii4.r).  In- 
deed in  the  case  of  the  last  mentioned 
pest  it  would  be  impossible  to  grow  this 
crop  in  forcing  houses  without  the  em- 
ployment of  remedial  measures. 

This  pest  can  be  held  in  control  by 
vaporization  or  fumigation  with  tobacco 
or  nicotine  extracts,  or  by  spraying  with 
kerosene  emulsion  or  the  so-called  whale- 
oil  (fish-oil)  soap.  Care  is  necessary  in 
using  the  extracts  that  the  smudge  does   Fi&.  lUx -Greenhouse 

,  ^1  J     •     •  it.  white   fly.     Adult    above, 

not   become    too   dense    and    mjure   the      p^p^  beiow-highiy  mag- 
plants.     Before  applying  this  remedy  on      "ified.  (After  Morrill.) 
a  large  scale  a  preliminary  trial  should  be  made  following  the 
directions  on  the  packages,  and  reducing  the  amount  if  any  ill 
results  follow.     Hydrocyanic  acid  gas  properly  used  is  an  ex- 
cellent remedy.^ 


1  See  Circ.  57,  Bu.  Entom..  U.   S.  Dept.  Agr.,  and  Fumigation  Methods,   by 
Prof,  W.  G.  Johnson,  publislied  by  Orange  Judd  Company,  New  York. 


CHAPTER    XI 

INSECTS    INJURIOUS    TO    CELERY,    PARSNIPS 
AND   RELATED   PLANTS 

A  CONSIDERABLE  number  of  insects  attack  celery,  but  few 
are  restricted  to  it  as  a  food,  and  fewer  yet  do  noticeable 
damage.  A  large  proportion  of  the  insects  which  live  on  it  also 
attack  carrot,  parsnip,  and  parsley,  preferring  one  or  the  other 
of  these  three  plants.  For  convenience,  however,  we  may  con- 
sider the  insect  enemies  of  celery  separately. 

INSECTS  INJURIOUS  TO  CELERY 

What  is  true  in  this  country  is  equally  true  in  Europe,  and 
there  is  little  danger  of  the  introduction  of  important  pests  from 
abroad.  With  the  increased  cultivation  of  this  crop  insects  which 
now  attack  it  may  increase  in  injuriousness.  but  there  is  no 
immediate  prospect  of  serious  losses  accruing  from  insect  at- 
tack. It  is  seldom  that  beds  of  celery  are  entirely  free  from 
the  celery  caterpillar;  the  same  may  be  said  of  the  zebra  cater- 
pillar. The  tarnished  plant-bug  is  one  of  the  worst  enemies 
with  which  the  celery  grower  has  to  contend,  but  its  having 
many  host  plants  usually  distributes  attack  except  in  unusual 
seasons.  Celery  generally  escapes  the  ravages  of  cutworms 
owing  to  its  late  planting  and  still  later  replanting,  and  neither 
white  grubs  nor  wireworms  deter  its  growth  as  far  as  observa- 
tions go,  presumably  because  of  its  powerful  root  and  root 
stalk.  The  leaves  are  attacked  by  leaf-rollers  and  leaf-tyers 
and  one  of  these,  the  celery  leaf-tyer,  is  of  considerable  im- 
portance. 

The  Carrot  Rust  Fly  {Psila  roscc  Fab.). — This  pest  has  been 
injurious  to  carrots   in   Canada   since   1885   and  made   its  ap- 

176 


INSECTS   INJURIOUS   TO   CELERY,    I'ARSNIP 


177 


pearance  in  1901  in  New  York  in  celery  fields.  In  attack  on 
celery  the  leaves  of  young  plants  early  in  spring  turn  reddish, 
and  the  roots  are  blotched  with  rusty  patches,  particularly 
toward  their  tips.  Roots  of  carrot  when  stored  for  winter,  al- 
though not  manifesting  any  degree  of  injury  on  the  outer 
surface,  are  at  times  perforated  in  all  directions  by  dirty  brown- 


Fig.  115.— Carrot  rust  fly.  S  •  Male  fly;  $  .  female  fly;  o,  antenna  of  male:  b,  full- 
grown  larva,  lateral  view;  c,  spiracles  of  same,  d.  anal  extremity;  e,  puparium;  /.  young 
larva;  g  anal  segment  from  side.  Flies,  young  and  mature  larva,  and  puparium,  eight 
times  natural  size;  other  portions  more  enlarged.  (Author's  illustration,  U.  S-  Dept. 
Agr.) 

ish  burrows,  from  which  these  whitish  yellow  maggots  may  be 
found  projecting.  When  celery  is  infested  the  larvae  seem  to 
begin  eating  into  the  thick  part  of  the  root  when  the  plant  is 
about  half  grown,  stunting  it  so  as  to  make  it  worthless  for 
market. 

This  species  is  quite  minute,  the  parent  fly  measuring  only 
about  one-sixth  of  an  inch  in  length,  with  a  wing  expanse  of 
a  little  more  than  three-tenths  of  an  inch.  The  body  is  dark 
green  and  is  rather  sparsely  clothed  with  yellow  hairs.  The 
head  and  legs  are  pale  yellow,  and  the  eyes  black.  The  two 
sexes  are  shown  at  S  and  ?,  figure  115.  According  to  Curtis, 
when  the  imago  issues  from  the  puparium  an  oval  lid  on  this 
portion  lifts  up,  permitting  the  fly  to  crawl  out.  The  posteiior 
extremity  ends  in  two  minute  dark  tubercles. 

The  carrot  rust  fly  is  a  pest  in  Europe,  whence  it  has  been 
introduced    in   this   country.      It    is   a   northern   species   and   is 


178  INSECTS    INJURIOUS   TO   VEGETABLES 

permanently  established  in  New  Brunswick.  Ontario  and  Que- 
bec, Canada,  besides  occuring  in  New  York  and  New  Hamp- 
shire.  " 

The  life  history  of  the  carrot  fly  has  not  been  entirely  worked 
out.  In  the  United  States  it  will  probably  be  found  to  pass 
the  winter  usually  as  a  puparium,  but  as  larvae  work  also  on 
carrots  in  store,  the  flies  develop  in  winter,  hence  we  have 
great  irregularity  in  development,  making  generalization  im- 
possible until  observations  are  made  in  the  field. 

The  insect  develops  rather  early  in  the  season  and  both 
flies  and  maggots  are  found  throughout  the  warmer  months, 
but  the  latter  desert  the  roots  for  pupation  in  the  earth,  the 
last  generation  probably  descending  much  deeper  than  the 
earlier  ones.  Curtis  states  that  the  summer  generations  develop 
in  three  or  four  weeks.  There  are  at  least  two.  and  probably 
more,  generations  annually.  Miss  Ormerod  has  observed  that 
the  female  fly  goes  down  into  the  ground  where  she  can  find 
a  crack  or  other  opening  about  the  roots  of  the  plant  affected. 
Here  she  lays  her  eggs,  and  the  maggots,  when  hatched,  work 
their  way  into  the  root;  when  this  is  quite  small  they  often 
destroy  the  lower  portion. 

METHODS    OF    CONTROL 

The  carrot  rust  fly  is  difficult  to  reach  with  insecticides.  Our 
principal  dependence  is  based  upon  methods  of  tillage  which 
will  avert  attack. 

Kerosene  emulsion  in  the  proportion  of  one  part  to  ten  of 
water  sprayed  upon  the  carrots  along  the  rows,  or  sand,  or 
ashes,  with  which  kerosene  is  mixed  at  the  rate  of  half  a  pint 
to  three  gallons,  sprinkled  along  the  rows,  have  given  good 
results.     These  substances  deter  the  fly  from  laying  her  eggs. 

Late  sowing  and  rotation  of  crops  are  excellent  remedies, 
as  is  also  the  planting  of  new  beds  as  far  as  possible  from 
land  infested  the  previous  season. 


INSECTS  INJURIOUS  TO  CELERY,  PARSNIPS,  ETC.    I79 

Destruction  of  stored  carrots. — Where  carrots  are  stored  for 
winter  use  in  earth  they  should  be  treated  to  destroy  the  larvae 
or  puperia.  This  may  be  accomplished  by  burying  the  earth 
deeply;  by  spreading  it  in  thin  layers  where  it  will  be  exposed 
to  the  elements ;  by  throwing  it  into  pools  where  it  will  be 
frozen;  or  by  exposing  it  to  heat  or  steam  in  any  convenient 
manner. 

Treatment  of  celery  beds. — As  this  insect  also  infests  celery, 
that  crop  should  not  follow  carrots  (nor  carrots  celery)  in 
rotation.  Clean  farming  should  be  practiced,  which  includes  the 
destruction  of  remnants  after  the  crop  has  been  harvested. 

After  harvest,  it  would  be  a  good  plan  to  give  celery  fields 
a  raking  or  cultivating  of  sufficient  depth  to  expose  the  larvae 
or  puparia  to  frost ;  early  the  following  spring,  before  the  flies 
issue,  if  the  earth  be  plowed  deeply,  it  will  have  the  effect  of 
destroying  such  insects  as  have  not  been  killed  by  frost  and 
survive  cultivating  and  raking. 

The  Celery  Caterpillar  (Papilio  polyxencs  Fab.). — Because  of 
its  large  size  and  brilliant  colors,  both  as  larva  and  adult,  this 
is  one  of  the  best  known  of  the  enemies  of  celery  and  allied 
plants.  The  caterpillar  is  green,  or  yellowish,  and  ringed  with 
black  and  spotted  with  yellow.  It  attains  a  length  of  two  inches. 
The  parent  insect  is  known  as  the  black  swallow-tail.  It  is 
velvet  black,  relieved  by  yellow  bands  in  the  male.  The  hind- 
wings  are  ornamented  on  the  interior  margin  by  eye-like  mark- 
ings like  those  of  the  peacock  and  the  wings  terminate  in 
the  tails  from  which  it  derives  its  common  name.  The  female 
is  somewhat  faded  black  and  of  more  sombre  appearance  than 
her  mate.  The  wing  expanse  is  about  three  inches.  The 
chrysalis  is  dull  gray,  mottled  with  dull  brown.  It  measures  a 
little  less  than  one  and  one-fourth  inches.  The  celery  cater- 
pillar is  one  of  the  most  interesting  insects  that  attack  garden 
plants.  It  appears  to  be  limited  to  no  special  life  zone,  occur- 
ring throughout  Canada  and  every  State  and  Territory  in  the 


l8o  INSECTS    INJURIOUS   TO   VEGETABLES 

Union,  southward  through  Central  America  and  the  West  Indies 
to  Venezuela.  The  young  larvae  are  utterly  dissimilar  to  the 
mature  ones,  and  five  distinct  stages  have  been  noted. 

This  insect  affects  practically  all  umbelliferous  crops,  celery, 
carrot,  parsley,  caraway,  fennel,  parsnip,  dill,  and  related  wild 
plants.  It  does  not  appear  to  attack,  except  in  extreme  cases, 
any  plant  outside  of  this  botanical  family. 

Remedies. — The  conspicuous  coloration  of  the  celery  cater- 
pillars renders  them  an  "easy  mark"  as  they  are  readily  found 
and  can  be  crushed  under  foot,  and  no  other  remedies  are 
necessary  if  the  work  of  destruction  is  begun  before  the 
plants  are  injured.  The  killing  off  of  the  first  generation  will 
serve  in  considerable  measure  to  destroy  the  insects  for  the 
second  brood,  if  this  work  be  done  over  a  considerable  area. 
The  butterfly,  however,  is  strong  of  flight,  and  cooperation  must 
be  had  to  keep  the  insect  in  check  when  it  becomes  destructive. 

The  Celery  Leaf-tyer  {Phlyctccnia  fcrrugalis  Hbn.)^ — This 
little  insect,  known  also  as  the  greenhouse  leaf-tyer,  first  came 
to  notice  as  a  pest  in  1888.  On  celery  it  feeds  by  preference 
on  terminal  leaves,  and  sometimes  burrows  into  the  stems.  On 
one  occasion  in  the  District  of  Columbia  it  was  so  destructive 
that  one  grower  had  determined  to  abandon  celery  culture  on 
this  account.  Next  year,  however,  the  insect  was  less  trouble- 
some ;  and  this  was  fortunate,  for  if  it  were  not  periodical  it 
might  be  a  very  bad  pest  indeed.  In  the  field  this  leaf-tyer 
attacks  besides  celery  cabbage,  beets,  tobacco,  lettuce,  cauli- 
flower, parsley,  cucumber,  sweet  pea  and  strawberry.  It  causes 
great  injury  to  many  greenhouse  plants — violet,  rose,  chrysan- 
themum, carnation,  ivy,  heliotrope,  and  others. 

The  moth  is  a  pale  reddish-brown,  expanding  about  three-fourths 
of  an  inch.  The  fore-wings  are  pale  clay  brown,  suffused 
with  reddish  or  ochreous  brown,  ornamented  with  black  lines 
(fig.  116,  a,  h).    The  hind-wings  are  gray,  with  darker  margins. 

1  For  a  detailed  account  see  Bui.  27,  Bu.  Entom.,  U.  S.  Dept.  Agr. 


INSECTS   INJURIOUS   TO   CELERY,   PARSNIPS,    ETC. 


i8] 


This  moth  resembles  that  of  the  garden  webworm  (page  6l). 
The  larva  is  green  or  greenish  yellow,  somewhat  translucent, 
with  whitish  head,  marked  with  purplish  dots  (fig.  Ii6,  e,  d,  f). 

This  is  an  introduced  species,  and  obviously  of  tropical  origin. 
Owing  to  its  adaptability  to  indoor  habits -it  is  likely  to  be 
found  anywhere. 

The  leaf-tyers  work  usually  on  the  under  surfaces  of  leaves, 
or  on  such  as  are  shaded  by  other  leaves.  When  young  they 
eat  out  small  holes  on  the  under  surfaces,  leaving  the  upper 


Fig.  11  6-— Celery  leaf-tyer.  a.  Moth;  b,  same  in  natural  position  at  rest;  c,  egg  mass; 
d,  larva  from  above;  e,  same  from  side;  /,  head  of  same;  g,  pupa  case;  h,  chrysalis. 
a,  b,  d,  e.  g,  h,  One-half  larger  than  natural  size;  c,  twice  natural  size;  /,  more  enlarged 
(original). 


epidermis  untouched;  but  as  they  increase  in  growth  the 
leaves  are  skeletonized  and  sometimes  entirely  devoured.  Larvae 
work  chiefly  at  night  and  rest  by  day  in  the  same  locations. 
They  prepare  for  transformation  to  pupae  by  spinning  up  be- 
tween two  leaves,  or  by  rolling  up  a  case  at  the  edge  of  a  leaf. 
(See  fig.  ii6,  g).  Owing  to  the  somewhat  secluded  manner 
of  life  of  the  larva,  attack  is  not  noticeable  until  considerable 
injury  is  done;  but  its  presence  can  be  readily  ascertained  by 
striking  the  plants  lightly,  when  the  moths  start  up,  fly  a  short 
distance,  then  alight,  and  disappear  under  a  leaf.  In  mid- 
summer the  entire  life  cycle,  according  to  the  writer's  observa- 


l82 


INSECTS    INJURIOUS   TO   VEGETABLES 


tions,  may  be  passed  in  five  weeks,  but  the  outdoor  spring  and 
fall  generations  require  a  longer  period.  There  are  at  least 
two,  and  frequently  three,  generations  produced  in  the  open; 
and  in  a  warm  equable  indoor  temperature  there  is  a  possibility 
of  four  and  perhaps  five. 

Remedies. — In  greenhouses  this  leaf-tyer  is  controlled  by 
trimming  away  and  destroying  infested  leaves  as  often  as  they 
are  detected.  The  moths  are  killed  in  great  numbers  by  placing 
lights  over  vessels  of  water  on  which  a  thin  scum  of  kerosene 
floats.  These  remedies  are  less  valuable  in  the  field,  but  Paris 
green  and  other  arsenical  sprays,  if  applied  at  ths  outset  of 


Fig.    1 1 7.— Celery  looper.      Male  moth  at  left,   larva  at  right.     Somewhat  enlarged 
(Author's  illustration,  U.  S.  Dept.  Agr.) 

attack,  will  destroy  the  larvae,  though  less  effective  after  they 
have  become  concealed  in  their  tied-up  leaves  and  in  the  growth 
of  leaves  about  them.  Spraying  should  be  thorough,  and  an 
underspray  is  desirable. 

The  Celery  Looper  (Plusia  simplex  Guen.). — This  species  is 
the  commonest  of  its  kind  in  Illinois,  and  is  rather  gierterally 
distributed  in  the  United  States  east  of  the  Rocky  Mountains, 
from  Canada  to  New  Mexico.  It  is  described  by  Messrs. 
Forbes  &  Hart  as  a  very  destructive  celery  insect,  and  occurs 
also  on  sugar  beet  and  lettuce. 

The  moth  (fig.  117)  has  a  greater  wing  expanse  than  the 
cabbage  looper,  measuring  nearly  two  inches,  has  different 
coloration,  and  differently  shaped  upper-wings.  The  border  of 
the  fore-wings  is  not  scalloped,  the  color  is  somewhat  purplish 


INSECTS   INJURIOUS   TO   CELERY,   PARSNIPS,    ETC.         183 

brown,  the  darker  shades  velvety  brown.  The  larva  is  similar 
to  the  cabbage  looper  and  similar  remedies  are  applicable. 

The  Little  Negro  Bug  (Corimelcena  pulicaria  Germ.). — This 
minute  black  bug  sometimes  does  considerable  damage  to 
celery,  as  happened  in  1893,  when  attack  was  quite  general 
throughout  the  celery-growing  portions  of  Michigan.  The 
insects  collect  in  clusters  around  the  nodes  where  the  three 
top  leaflets  meet.  Here  they  suck  the  sap  until  the  leaflets 
wilt  and  droop,  after  which  they  go  to  the  joint  below  and 
repeat  the  operation  till  the  leaf  is  drained  of  sap. 

The  mature  negro  bug  measures  only  about  an  eighth  of  an 
inch,  and  is  glossy  black,  the  scutellum  occupying  over  half  of 
the  upper  surface  and  being  surrounded  by  a  white  margin.  This 
insect  is  common  and  well  distributed.  It  prefers  old  celery 
when  about  ready  for  blanching  and  plants  are  retarded  in 
growth  from  two  to  three  weeks,  recovering  with  large  numbers 
of  small  curling,  gnarly  stalks  of  little  or  no  market  value. 
In  such  cases  the  crop  is  practically  an  entire  loss.  This 
species  is  a  general  feeder  attacking  numerous  garden  plants, 
among  which  are  strawberry  and  blackberry,  and  it  is  due  in 
part  to  this  insect  that  these  berries  sometimes  have  such  a 
disgustingly  sour  taste,  and  "buggy"  odor,  particularly  when 
picked  in  the  field. 

Remedies. — Carbolic  or  kerosene  emulsion  are  useful  both 
as  destroyers  and  repellents.  In  experiments  conducted  by  Mr. 
■  G.  C.  Davis,  the  bugs  were  readily  killed  with  hot  water  at  a 
temperature  of  155°  F..  acid  the  celery  plants  were  found  to 
endure  a  stream  heated  to  175°.  This  remedy  is  most  effective 
when  the  insects  first  appear  and  when  applied  on  the  plants 
where  they  are  most  numerous.  It  necessitates  the  use  of  a 
thermometer  that  the  temperature  may  not  go  above  175°. 
Celery  should  not  be  planted  in  the  vicinity  of  weedy  fields, 
especially  those  containing  umbellifers,  as  these  harbor  the 
insects  sometimes  in  enormous  numbers. 


184  INSECTS    INJURIOUS    TO    VEGETABLES 

INSECTS  INJURIOUS  TO   CARROTS,  PARSNIPS 
AND    PARSLEY 

In  this  category  we  include  parsley  although  it  does  not 
seem  to  have  any  insect  enemies  of  its  own.  These  plants 
belong  to  the  same  family  (Umbelliferse)  as  celery,  and  as 
stated  in  a  preceding  page  most  of  the  insects  enumerated  as 
affecting  that  plant  are  liable  to  attack  these  also,  but  both 
parsnip  and   carrot   have   particular   species   that   infest   them, 


Fig.  118.— Parsnip  leaf-miner,    a,  Fly;  b,  larva;  c.  cephalic  extremity  of  larva;  (/,  anal 
extremity;  e,f,  spiracles-    All  enlarged.    (After  Coquillett,  U.  S.  Dept.  Agr.) 

because  they  are  planted  for  their  roots  and  not  for  their 
delicate  stalks,  as  in  the  case  of  celery,  which  renders  the  por- 
tions above  ground  more  rank  and  those  below  ground  more 
tender,  while  each  plant  (parsnip  and  carrot)  has  a  flavor 
peculiar  to  itself.  Thus  it  happens  that  the  leaves  of  parsnip  are 
more  affected  by  the  parsnip  leaf-miner,  while  the  roots  of 
carrot  are  preferred  by  the  carrot  beetle  and  carrot  rust  fly. 
The  Parsnip  Leaf -miner  (Acidia  fratria  Loew.). — The 
economic  history  of  this  species  begins  with  1891,  when  parsnip 
leaves,  in  Missouri  were  quite  extensively  mined  by  its  larva. 


INSECTS    INJURIOUS    TO    CELERY,    PARSNIPS,    ETC.         185 

The  adults  issued  June  23.  The  insect  which  produces  this 
maggot  is  shown  at  figure  118,  «.  It  belongs  to  the  same  family 
as  the  apple  maggot  or  railroad  worm,  and  it  will  be  seen  that 
it  is  a  two-winged  fly,  with  rather  prettily  marked  vv'ings.  It  is 
pale  dull  yellow,  and  the  wings  are  marked  with  the  same  color. 
The  legs  are  still  paler,  and  the  eyes  are  brown.  The  head  and 
thorax  above  bear  long,  stiff  bristles.  This  fly  measures  about 
three-sixteenths  of  an  inch  in  length,  and  has  a  wing  expanse 
at  least  double  that.  It  ranges  from  the  Atlantic  seaboard 
westward  to  Missouri  and  probably  farther.  Little  is  known 
of  its  life  history,  but  it  will  probably  be  found  to  affect  other 
umbelliferous  crop  plants  and  weeds. 

Remedies  advised  against  the  radish  leaf-miner   (page  154) 
are   applicable. 

The  Carrot  Beetle  (Ligynts  gibbosus  DeG.). — This,  beetle  is 
the  worst  insect  enemy  to  carrot  and  parsnip  in  this  country. 
It  is  a  native  species  and  of  common  oc- 
currence along  the  Atlantic  Coast  from 
Long  Island  to  the  Gulf  and  Pacific  States 
and  at  many  points  inland.  It  injures  be- 
sides the  plants  specified  various  root 
crops  and  some  other  plants. 

The  beetle  might  be  mistaken  for  a  May 
beetle,  but  the  wingcovers  are  strongly 
sculptured  and  coarsely  punctate,  char- 
acters which  are  wanting  in  true  May  ^.^  Ti  9.  Carrot  feetie. 
beetles  (Lachnosterna).  The  beetle  (fig.  About  twice  natural  size. 
1 19)  is  of  robust  form,  measuring  between  J.^^^^^X^r.'^"''"""" ""'  ^' 
one-half   and   five-eighths   of    an    inch    in 

length,  with  short  legs.  The  color  varies  from  reddish  brown 
to  nearly  black  on  the  dorsal  surface.  Larval  injury  has  been 
noted,  but  there  is  little  doubt  that  the  grubs  feed  also  on  humus, 
manure  and  decomposing  roots  and  tap  roots  of  herbaceous 
plants.    Larv?e  have  been  observed  to  feed  on  earth  where  there 


1 86  INSECTS    INJURIOUS   TO    VEGETABLES 

was  no  opportunity  for  plant  attack.  Most  cases  of  injury  are 
due  to  the  operations  of  the  beetles,  and  damage  is  more  pro- 
nounced on  young  plants,  older  growth  appearing  in  some  cases 
exempt  from  attack,  owing  to  its  more  woody  texture.  Injury 
may  be  accomplished  both  by  hibernated  individuals  in  the 
spring  from  April  to  June,  according  to  locality,  and  by  recently 
transformed  specimens  in  late  summer  and  autumn. 

The  species  is  with  little  doubt  single-brooded.  Pupation 
takes  place  in  an  oval  cavity  in  the  earth,  and  hibernation, 
without  much  doubt,  occurs  ifi  the  adult  condition.  The 
favorite  food  of  the  beetle  is  evidently  carrot,  and  after  this 
corn,  parsnip  and  celery  are  chosen.  Sweet  and  Irish  potato 
are  subject  to  much  damage,  as  are  also  sunflower,  dahlia,  sugar- 
beet  and  sometimes  cotton.  The  beetles  usually  feed  beneath 
the  surface;  corn  is  cut  just  above  the  roots,  and  root  crops  are 
punctured  with  holes.  Sometimes  a  crop  appears  in  good  condi- 
tion, judging  from  the  tops  alone,  but  when  the  plants  are 
pulled  injury  becomes  manifest.  Entire  plantings  have  been 
destroyed  by  the  beetles,  and  the  roots  of  tubers  rendered  un- 
marketable on  account  of  their  ravages.  They  gnaw  into  the 
roots  of  celery,  dwarfing  and  killing  the  plants,  and  eat  the 
bark  from  the  root.  They  sometimes  imbed  themselves  in  tap 
roots  and  may  penetrate  the  earth  to  a  depth  of  seven  inches. 
As  many  as  fifty  beetles  have  been  found  about  the  roots  of 
a  single  plant. 

Methods  of  Control. — When  this  insect  is  present  in  large 
numbers  there  is  little,  owing  to  its  working  underground,  that 
can  be  accomplished  in  the  line  of  control.  The  beetles  are 
strongly  attracted  to  electric  lights,  but  it  is  not  certain  that 
they  could  be  lured  from  the  field  after  beginning  to  feed.  It 
is  reported  that  lime  scattered  through  infested  fields  has  ap- 
parently driven  the  beetles  away.  After  the  crop  has  been  har- 
vested, if  the  insects  continue  in  numbers  in  the  ground,  it  would 


INSECTS    INJURIOUS    TO    CELERY,    PARSNIPS,    ETC. 


[87 


be  profitable  to  turn  in  hogs  or  chickens.     Crop  rotation  and 
other  white-grub  remedies  should  be  practiced. 

The  Parsnip  Webworm  (Depressaria  heracliana  DeG.).— The 
parsnip  webworm  is  injurious  to  the  seed  of  parsnip,  but  for 
some  reason,  at  least  in  the  experience  of  the  writer,  prefers 
the  wild  carrot  as  a  breeding  plant.  The  moth  is  grayish  buff, 
or  pale  ochraceous.  with  the  fore-wings  marked  with  fuscous 
(fig.  120,  c).  The  larva  is  pale  yellow,  greenish  or  bluish  gray, 
marked  with  black,  piliferous  spots,  and  with  bluish  black  head 


Fig.  120.— Parsnip  webworm.  a,  MoTh;  b.  c,  caierpillars:  (^.chrysalis:  e  anal  segment 
of  same:  /.  umbel  of  parsnip,  webbed  together  by  caterpillar,  a  e.  Enlarged;  /,  some- 
what reduced.    (After  Riley  ) 


and  thoracic  plate,  as  figured  (0,  b).  The  species  is  of  general 
occurrence  through  the  northern  portions  of  Europe  and  our 
Atlantic  States  and  Canada  westward  to  Michigan.  Wild 
carrot  and  parsnip,  which  are  altogether  too  abundant  in  fields 
throughout  that  section,  yield  it  a  sufficiency  of  food  and  in  some 
years  it  is  difficult  to  find  these  weeds  that  are  not  affected 
by  the  webworm.  The  larvae  weave  the  flower  heads  (/) 
together  until  these  are  contracted  into  masses,  with  abundant 
excrement  as  a  covering.  Within  the  domicile  thus  formed  the 
larvae  dwell.    After  they  have  consumed  the  flowers  and  unripe 


l88  INSECTS    INJURIOUS    TO   VEGETABLES 

seeds  and  are  nearly  mature,  they  enter  the  stems,  feed  on  the 
soft  lining,  and  transform  to  pupae.  They  sometimes  destroy 
newly-sown  parsnip,  eating  the  tender  leaves,  but  in  attack  on 
older  plants  they  eat  the  umbels  or  flower  heads  and  the  inte- 
rior of  the  stems. 

Remedies. — A  thorough  spraying  with  arsenicals  will  destroy 
this  webworm.  To  prevent  injury  by  it  avoid  planting  parsnips 
in  or  near  waste  places  which  have  become  overrun  with  wild 
carrot. 

Miscellaneous  Insects. — Among  other  insects  injurious  to 
celery  the  tarnished  plant-bug  is  an  important  species.  It  is 
figured  and  described  on  pages  87  and  88.  The  cotton  leaf-bug 
(Calocoris  rapidus  Say),  a  species  of  somewhat  similar  habits 
and  appearance  (fig.  120.1:),  also  attacks  celery  and  is  amenable 
to  the  same  remedial  treatment. 


CHAPTER    XII 

INSECTS  INJURIOUS  TO  SWEET  CORN 

A  GREATER  number  of  species  of  insects  have  been  recognized 
as  attacking  Indian  corn  than  any  other  plant  grown  as  a 
vegetable.  Although,  properly  speaking,  corn  is  a  field  crop,  it 
is  also  grown  for  the  sake  of  the  unripe  ears  which  are  classi- 
fied as  vegetables.  What  insects  will  attack  field  corn  will 
also  attack  the  garden  variety,  but  for  present  purposes  it  will 
not  be  necessary  to  treat  of  any  except  the  more  important 
habitually  garden-inhabiting  species,  and  only  a  few  of  these 
need  be  considered  at  all  in  detail.  Many  of  them  are  general 
feeders  and  have  been  considered  in  preceding  paragraphs. 

The  corn-feeding  species  of  insects  recognized  in  1896  were 
214  in  number,  and  of  these  18  attacked  the  seed,  27  the  root 
and  lower  portions  of  the  stalk,  76  the  stalk  above  ground,  118 
the  leaf,  19  the  tassel  and  silk,  and  42  the  ear.  The  remainder 
attacked  the  stored  product.  It  is  safe  to  say  that  at  the  present 
writing  (1907)  at  least  350  species  are  on  record  as  concerned 
in  attack  on  corn. 

The  Corn  Root-aphis  (Aphis  maidiradicis  Forbes). — Con- 
cerning this  species.  Dr.  S.  A.  Forbes  wrote  in  1896:  "No  in- 
sect affecting  corn  is  more  deserving  of  the  attention  of  farmers 
and  entomologists  at  the  present  time  than  the  corn  root-aphis. 
It  ranks  as  a  corn  pest  with  the  chinch  bug  and  the  army  worm, 
less  injurious  at  any  one  time  than  these  are  locally  and  occa- 
sionally, but  overtaking  them,  on  the  other  hand,  by  its  general 
distribution  and  the  constancy  of  its  attack."  This  root-aphis 
does  its  principal  injury  while  corn  is  small.  The  dwarfing  of  a 
plant  in  patches  with  a  yellowing  or  reddening  of  the  leaves,  and 

i8q 


190  INSECTS    INJURIOUS    TO    VEGETABLES 

a  lack  of  thrift  and  vigor,  are  the  outward  manifestations  of 
injury.  Another  indication  is  the  presence  of  numerous  small 
brown  ants  which  attend  this  species  and  without  which  it 
probably  could   not  exist. 

The  corn  root-aphis  is  bluish  green,  slightly  whitened  by  a 
waxy  bloom.     The  body  is  oval,  and  the  nectaries  are  erect  or 


Fig.   121.— Winged  viviparous  female  of  corn  root-aphis;  wingless  egg-laying  female- 
Enlarged.    (After  Forbes) 

project  slightly  backwards.  Two  of  the  different  forms  are 
shown  in  figure  121.  It  is  found  from  Massachusetts  to  Minne 
sota  and  Nebraska  and  as  far  south  at  least  as  Virginia. 

The  winged  forms  migrate  to  various  weeds,  among  which 
are   smartweed,   pigeon  grass,   mustard,   pigweed  and   plantain. 

Economic  Treatment. — Our  present  knowledge  of  this  insect 
suggests  several  methods  of  attacking  it.  Crop  rotation  and 
care  not  to  plant  in  or  near  fields  of  weeds  which  serve  as 
alternate  hosts ;  the  free  use  of  manures  and  other  fertilizers  to 
stimulate  the  growth  of  the  plants ;  the  disturbing  and  destruc- 
tion of  the  nests  of  the  protecting  ants ;  the  destruction  of  all 
of  the  weeds  which  serve  the  aphides  as  food  early  in  the 
season  by  plowing,  and,  in  connection  with  this,  late  planting 
of  corn.'  Such  measures  of  procedure  may  not  entirely  pro- 
tect the  crops  in  all  localities  in  all  seasons. 

1  These  and  other  remedies  are  considered  in  detail  by  F.  M.  Webster  in 
Circ.  86,  Bu.  Entom.,  U.  S.  Dept.  Agr. 


INSECTS   INJURIOUS  TO  SWEET   CORN  I9I 

The , Southern  Corn  Root-worm  (Diabrotica  12-punctata  01.)- 
• — The  larvit  of  two  species  of  leaf-beetles  are  among  the  promi- 
nent enemies  to  the  culture  of  corn  by  destroying  the  roots. 
One  of  these,  the  Southern  corn  root-worm  is  common  nearly 
throughout  the  United  States,  but  as  its  name  implies  is  most 
destructive  in  the  South.  In  the  case  of  its  attack  not  alone 
roots,  but  underground  stalks  are  injured.  The  other,  known 
as  the  Western  corn  root-worm,  is  somewhat  confined  to  the 
middle  West,  where  it  w^ould  be  a  very  serious  pest  were  it 
not  that  farmers  generally  in  that  region  have  adopted  a  sys- 
tem of  rotation  which  greatly  reduces  injury.  The  principal 
form  of  its  attack  is  in  the  interior  of  the  fibrous  roots,  in  which 
minute,  more  or  less  longitudinal,  burrows  are  formed. 

The  larva  of  the  .Southern  species  is  also  called  in  the  South 
the  "bud-worm"  and  "drill-worm."  The  beetle  is  commonly 
known  northward  as  the  twelve-spotted  cucumber  beetle  be- 
cause of  its  frequenting  the  flowers  of  cucumber,  as  well  as 
squash,  and  other  cucurbits  in  the  interior  of  which  one  can 
usually  see  one  or  more  dusted  with  pollen,  and  the  places  where 
they  have  gnawed  the  petals,  for  they  are  most  omnivorous  in- 
sects and  able  to  subsist  on  nearly  any  form  of  vegetation  on 
which  they  happen  to  alight.  They  are,  in  fact,  to  be  found  in 
practically  all  fields  of  corn  and  in  gardens  everywhere. 

The  beetle  is  yellowish  green,  and  the  wing-covers  are 
marked  with  twelve  black  spots  (fig.  122,  a).  The  length  is 
one-quarter  of  an  inch  or  a  little  longer.  The  larvae  (c)  are 
slender,  thread-like,  delicate  and  soft  bodied,  and  white  or  yel- 
lowish in  color. 

The  twelve-spotted  cucumber  beetle  inhabits  that  portion  of 
America  lying  between  the  Atlantic  seacoast  to  the  base  of  the 
Rocky  Mountains,  and  from  Canada  to  Mexico.  It  is  a  very 
common  species  and  most  destructive  in  the  South,  where  in- 
jury is  accomplished  by  its  root-worm  form  as  far  northward 
as  Maryland  and  Virginia. 


[92 


INSECTS    INJURIOUS    TO   VEGETABLES 


The  adult  is  practically  omnivorous,  its  known  food  ma- 
terials are  legion,  and  include  besides  the  pollen  and  flowers 
and  partly  matured  kernels  of  corn,  wheat  and  oats,  the  foliage 
of  alfalfa,  crimson  clover,  cotton,  rye  and  tobacco.  Of  vege- 
tables it  attacks  all  forms.  It  frequently  injures  the  fruit  of 
melon  and  other  cucurbits.  Larv?e  or  pupae  have  been  ob- 
served at  the  roots  of  corn,  wheat,  rye,  millet,  beans,  rudbeckia 


Fig.  122.— Southern  corn  root-worm.  a.  Beetle:  b.  egg;  c,  larva;  d,  last  segment  of 
same;  e  section  of  cornstalk  showing  holes  made  by  larvae;  /,  pupa,  a,  c  /,  Consider- 
ably enlarged;  i,  rf,  more  enlarged;  tf,  reduced,  (a-c/,  After  Riley;  e,/,  redrawn,  U.  S. 
Dept.  Agr.) 


and  sedges.  In  fields  of  corn  this  root-worm  gives  origin  to 
the  loss  of  roots,  injury  varying  according  to  the  age  of  the 
corn  and  severity  of  attack,  and  somewhat  also  upon  the  con- 
dition of  the  weather,  and  even  of  the  soil.  Injury  is  mani- 
fested in  various  ways :  from  the  death  of  a  plant  to  re- 
tardation of  growth,  or  to  what  is  termed  "spindling,"  or  a 
yellowish,  unhealthy  look.  In  plants  six  inches  or  less  in 
height  the  perforations  of  the  stalk  (fig.  122,  c)  are  character- 


INSECTS  INJURIOUS  TO  SWEET  CORN  I93 

ibtic,  and  usually  show  just  below  the  surface.  This  is  ac- 
complished by  more  or  less  withering  of  the  plant,  which  is 
frequently  killed  outright  by  the  destruction  of  the  central 
tuft  of  growing  leaves.  Frequently  plants  are  destroyed  al- 
most as  soon  as  sprouted.  Should  the  plants  survive  ordinary 
attack  they  are  apt  to  fail  to  produce  mature  ears.  If  plants 
which  are  suspected  of  harboring  this  species  are  pulled  up,  the 
root-worms  can  be  dislodged,  and  it  is  not  difficult  to  distinguish 
them  from  other  forms  of  insects  found  in  the  same  locations, 
with  the  exception  of  the  western  corn  root-worm,  which, 
however,  seldom  occurs  in  the  same  regions. 

The  beetle  is  one  of  our  earliest  as  well  as  latest  species. 
Indications  are  that  at  least  two  and  perhaps  three  generations 
are  produced  annually  in  the  District  of  Columbia,  and  prob- 
ably four  in  the  insect's  more  southern  range.  Eggs  are  laid 
at  the  base  of  the  insect's  food  plant  and  have  been  observed 
by  the  writer  to  hatch  in  six  and  seven  days  in  cool  May 
weather. 

Remedies. — We  cannot  reach  the  insect,  to  any  extent,  by 
means  of  poisons  and  their  use  on  growing  corn  is  impractica- 
ble. Therefore,  we  must  have  recourse  to  farm  methods. 
Injury  to  corn  is  greatest  when  seed  is  planted  in  bottom  lands, 
and  if  planting  is  necessary  in  such  locations  it  should  be  done 
late,  in  the  Gulf  region  by  the  first  of  May,  or  attack  may  be 
so  distributed  that  damage  will  be  inconsequential,  by  dropping 
about  ten  grains  of  seed-corn  in  each  hill.  Of  greater  import- 
ance, however,  is  judicious  crop  rotation.  Numbers  of  crops 
are  not  injured  by  the  Southern  corn  root- worm,  and  can  be 
used  as  alternates.  Of  these  are  cotton,  buckwheat,  smaller 
grains,  and  vegetables  other  than  beans  and  cucurbits.  In 
the  occurrence  of  the  beetles  on  cucurbits  remedies  advised 
against  the  striped  cucumber  beetle  should  be  used.  (See 
page  158.)  On  beans  a  spray  of  arsenate  of  lead  should  be 
employed, 


194  INSECTS    INJURIOUS    TO   VEGETABLES 

The  Western  Corn  Root-worm  {Diabrotica  longiconiis  Say.). 
^NotwiUistancling  the  general  employment  of  crop  rotation 
as  a  means  of  preventing  losses  by  this  species,  inflicted  in- 
juries are  reckoned  by  millions  of  dollars  annually.  Thus  in 
1885  the  damage  to  corn  in  24  counties  of  Indiana  was  esti- 
mated at  $2,000,000.  Corn  is  the  only  food  plant  of  the  larva, 
but  the  beetles  are  somewhat  more  choice  in  food  habits  than 
the  Southern  species.  In  the  experience  of  the  writer  and 
some  others,  they  are  partial  to  thistle  blossoms,  in  which  they 


F!g.  123.— Western  corn  root-worm.    a.  Beetle:  b,  larva,  from  side;  c,  leg  of  same;  d, 
pupa.    All  much  enlarged;  c,  more  enlarged.   (Author's  illustration,  U.  S-  Dept.  Agr.) 

deeply  imbed  themselves,  to  sunflower  and  goldenrod,  and  are 
less  frequently  found  on  cucurbits.  The  beetles  do  some  dam- 
age to  corn  by  feeding  on  the  pollen  and  gnawing  the  silk 
and  tassels,  thus  to  a  certain  extent  preventing  cross-fertiliza- 
tion and  causing  a  partial  blasting  of  ears.  Other  plants  such 
as  ragweed  and  smartweed  arc  frequented  for  the  sake  of 
pollen.  In  late  fall  and  early  winter  the  beetles  have  the  same 
habit  as  the  twelve-spotted  and  striped  cucumber  beetles  of 
gnawing  into  squash  and  pumpkin  in  the  field. 

This  species  is  evidently  single-brooded.  The  beetles  occur 
in  the  field,  like  the  Southern  species,  until  November,  in  open 
winters  as  late  as  the  middle  of  December,  which  is,  in  the 
writer's  opinion,  proof  positive  that  the  beetles  hibernate,  but 


INSECTS  INJURIOUS  TO  SWEET   CORN  I95 

as  a  rule  the  species  passes  the  winter,  according  to  Forbes,  in 
the  eggs  which  are  deposited  in  the  earth. 

The  developing  larvae  live  entirely  beneath  the  surface,  min- 
ing the  fibrous  roots,  and  seem  capable  of  traveling  from  one 
root  to  another;  pupation  also  takes  place  underground.  The 
beetles  of  the  new  generation  begin  to  issue  during  the  latter 
part  of  August. 

Prevention  and  Remedy. — This  species  is  more  readily  con- 
trolled than  the  Southern  corn  root-worm;  injury  can  be  pre- 
vented by  simply  following  crop  rotation.  Since  the  insect 
feeds  in  its  larval  condition  on  corn  alone,  the  planting  of  in- 
fested land  to  other  crops  leads  to  its  starvation.  It  is  im- 
prudent to  plant  corn  in  fields  or  meadows  in  which  the  beetle 
has  been  observed  in  abundance  in  au- 
tumn of  the  previous  year.  Another 
measure  is  recommended,  as  a  general 
farm  practice,  the  maintenance  of  the 
fertility  of  the  soil  by  the  use  of  manures 
and  other  fertilizers.  Although  this  does 
not  diminish  attack,  it  enables  the  plant 
to  withstand  injury. 

THE  CORN  BILL-BUGS 

Bill-bugs,  like  wireworms  and  white- 
grubs,  follow  the  planting  of  corn  in  sod 
and  bottom  land  or  in  the  immediate  vi- 

Fig.     124.— The    calloused 

cinity  of  streams  in  which  sedges,  rushes  com  bui-bug  (Sphempho- 
and  similar  wild  vegetation  grow  rankly.     '^^  callosus).     (Author's 

^^  *'  -'         illustration.) 

They  are  an  adjunct  to  the  reclamation  of 

swamp  tracts  and  receive  their  name  from  the  long  "bills" 
which  they  bear.  They  are  snout-beetles  and  related  to  weevils 
and  curculios.  Several  species  are  troublesome  in  corn-growing 
regions,  and  were  it  not  that  they  are  exceptionally  periodical 
they  would  take  high  rank  with  the  important  enemies  of  this 


196  INSECTS    INJURIOUS    TO   VEGETABLES 

crop.  A  year  or  two  after  the  first  attack,  the  beetles  usually 
disappear,  since  only  a  few  species  live  in  the  larval  stage  on 
corn.  The  larvae  feed  at  the  roots  and  in  bulbs  of  the  forms 
of  vegetation  that  have  been  mentioned,  which  include  nut-grass 
and  various  true  grasses  such  as  timothy.  The  greatest  injury 
is  due  to  the  perforation  of  stalks  of  corn  just  at  or  below  the 
surface  when  plants  are  only  two  or  three  inches  high.  The 
beetles  sink  their  beaks  deeply  through  the  unfolded  blades  so 
that  when  these  unroll  little  rows  of  both  round  and  elongate 
longitudinal  holes  are  left  as  evidence  of  earlier  attack.  As  with 
injury  by  root- worms  and  some  other  insects  which  live  in  more 
or  less  concealment  at  or  below  the  soil  surface,  close  scrutiny 
is  necessary  in  order  to  detect  bill-bugs,  and  damage  which  is 
usually  first  manifested  by  the  wilting  and  dying  of  plants  and 
their  stunted  growth  is  apt  to  be  attributed  to  other  causes. 
The  habits  of  these  insects,  in  common  with  other  snout-beetles 
when  disturbed,  of  drawing  their  antennae  and  legs  closely  to 
their  bodies,  and  of  their  bodies  being  frequently  more  or  less 
covered  with  dirt,  are  of  assistance  in  their  concealment.  A 
common  injurious  form  is  shown  in  figure  124. 

The  Southern  Corn  Bill-bug  (Sphciwphorus  maidis  Chittn.) 
is  one  of  the  most  pernicious  bill-bugs,  and  a  good  example  of 
a  species  that  lives  in  its  larval  as  well  as  adult  stage  on  corn. 
It  is  most  destructive  in  lowlands  and  occurs  in  the  Gulf  region 
and  in  Kansas.  Of  the  habits  of  this  species  Dr.  L.  O.  Howard 
says  substantially : 

"Wherever  the  larva  had  reached  full  size,  the  pith  of  the 
stalk  was  completely  eaten  out  for  at  least  five  inches.  Below 
ground,  even  the  hard,  external  portions  of  the  stalk  were 
eaten  through,  and  in  one  instance  everything  except  the  root- 
lets had  disappeared,  and  the  stalk  had  fallen  to  the  ground.  In 
a  great  majority  of  instances  a  single  larva  was  found  in  a 
stalk,  but  in  a  few  cases  two  larvae  were  at  work.  In  no  case 
had  an  ear  filled  on  a  stalk  bored  by  this  larva.     The  stalk 


INSECTS    INJURIOUS   TO    SWEET    CORN  I97 

was  often  stunted  and  twisted,  and  the  lower  leaves  were  in- 
variably brown  and  withered." 

From  examination  of  numbers  of  stalks  it  is  evident  that  eggs 
are  laid  in  them  near  the  soil  surface,  and  the  young  larvae 
usually  work  downwards.  The  presence  of  larvae  in  the  stalks 
proper  is  apparently  only  after  the  roots  and  the  pith  below 
ground  have  been  exhausted.  The  beetle  (fig.  125,  c,  d)  is  black, 
and  has  the  thorax  marked  with  three  raised  lines.  The  length 
is  about  half  an  inch  exclusive  of  the  snout,  which  measures 
about  one-sixth  of  an  inch.     The  larva  is  of  about  the  same 


Fig.   125.— The  Southern  corn  bill-bug.      a,  Larva;  b,  pupa;  c,  beetle,  from  above;  d, 
same  from  side.    All  slightly  enlarged.    (From  Riley,  U.  S.  Dept.  Agr.) 

length  as  the  beetle,  nearly  white,  of  the  peculiar  curved  form 
shown  at  a,  the  head  being  a  little  darker  and  the  mouth-parts 
still  darker. 

The  Northern  Corn  Bill-bug  (Sphenophonts  zca:  Walsh)  is 
somewhat  restricted  to  the  north  as  regards  injuries.  The  adults 
alone  injure  corn,  the  larvae  subsisting  on  the  roots  and  bulbs  of 
timothy  and  other  grasses.  In  1891  the  writer  investigated  an 
invasion  of  this  species  in  Chester  County,  Pennsylvania,  where 
the  beetles  were  attacking  newly-planted  corn  just  beneath  the 
surface.  As  was  surmised  before  visiting  this  point,  a  stream 
of  water  was  running  close  at  hand  in  the  marshy  soil  where 
rank  vegetation  grew  in  profusion,  including  different  forms 
of  sedges,  rushes,  weeds  and  wild  grasses,  the  obvious  original 
starting  place  of  the  insect.  The  principal  damage 'was  done  to 
cornfields  located  from  fifty  to  one  hundred  feet  above  the  creek 


198  INSECTS    INJURIOUS   TO  VEGETABLES 

bed.  In  one  field  not  a  single  plant  had  escaped  attack.  Ap- 
proximately 50  per  cent,  of  the  plants  had  been  killed  outright, 
and  25  per  cent,  of  the  remainder  were  so  severely  damaged  as 
to  necessitate  replanting.  In  some  fields  a  second  replanting 
had  been  necessary.  In  the  latter  days  of  May  the  bill- 
bugs  were  in  the  height  of  their  work  of  demolition,  and  had 
nearly  ceased  by  the  second  week  of  June. 

The  Clay-colored  Bill-bug   (Sphenophorus  cequaUs  Gyll.)^ — 
This  species   (fig.   126)   resenbles  the  preceding  in  depredating 


Fig.   126. — Clay-colored  biM-bug.    u.  Beetle;  i,  work  iniushbulb;  c,  larva 
(Insect  Life,  U.  S.  Dept.  Agr.) 

on  corn  only  in  the  adult  stage,  its  larva  developing  in  the  bulbs 
of  club  rush  and  related  plants.  It  is  the  largest  of  our  in- 
jurious corn-feeding  species  of  this  group. 


METHODS    OF    CONTROL 

Injury  to  other  crops  than  corn  by  bill-bugs  is  comparatively 
insignificant,  and  the  same  holds  of  the  larvae.  The  beetles 
are  the  occasion  of  the  greatest  losses  when  corn  is  first 
planted  and  their  amazing  vitality  makes  it  difficult  to  combat 
them  with  poisons  which  are  practically  inert. 

1  Mentioned   in   economic   literature   as   Sph.    ochreits   Lee. 


INSECTS    INJURIOUS   TO    SWEET    CORN  I99 

Bill-bug  injury  in  general  may  be  avoided  by  not  planting 
corn  in  land  already  liable  to  be  infested,  such  as  swampy 
ground,  river  bottoms,  or  in  soil  in  which  rank  grasses  and 
sedges  are  growing.  Before  planting,  such  ground  should  be 
thoroughly  broken  up  and  grown  to  some  crop  which  the 
beetles  will  not  injure.  Bill-bugs  so  far  as  known  injure  only 
corn,  rice,  timothy,  nut-grass  and  other  grasses,  and  occasionally 
smaller  grain.  Cotton,  tobacco,  buckwheat,  potatoes  or  other 
garden  vegetables,  or  other  crops  than  those  mentioned  as 
susceptible  to  bill-bug  attack,  will  serve  as  alternates. 

Direct  remedies  are  possible  against  bill-bugs  whose  larvae 
also  injure  corn.  One  of  these  consists  in  plowing  up  and 
burning  infested  stubble,  when  the  larvae  are  present  in  such 
numbers  that  the  ruin  of  a  crop  is  assured.  This  should  be 
done  late  in  July  or  early  in  August  for  most  localities, 
before  the  insects  have  matured  and  issued  from  the  stalks 
as  adults.  Some  species,  e.  g.,  the  Southern  corn  bill-bug,  pass 
the  winter  as  adults  in  the  stubble  and  for  these  burning  over 
the  fields  as  soon  after  harvest  as  possible  is  indicated.  In  the 
case  of  the  Northern  bill-bug  do  not  plant  corn  after  timothy. 

The  Common  Stalk-borer  (Papaipcma  nitela  Gn.). — This  in- 
sect enjoys  the  distinctive  designation  of  the  stalk-borer,  but 
it  has  numerous  other  names  of  which  are  the  heart-worm  and 
potato  stalk-borer.  Although  a  general  feeder,  it  is  quite  as 
commonly  found  attacking  corn  as  other  crops,  hence  may  be 
mentioned  in  connection  with  the  two  species  that  have  just  been 
considered. 

The  moth  (fig.  127,  0)  is  medium  gray-brown  or  fawn  color, 
and  marked  as  shown.  The  growing  larva  (&)  is  peculiar  in 
having  the  first  three  or  four  abdominal  segments  suffused  in 
such  a  manner  as  to  give  it  the  appearance  of  being  diseased. 
The  mature  larva  measures  about  an  inch  and  a  half  and  has 
more  or  less  the  appearance  shown  at  c.  The  abdominal  seg- 
ment of  the  larva  is  shown  at  d,  while  at  c  is  shown  the  female 


200 


INSECTS    INJURIOUS   TO   VEGETABLES 


chrysalis.  This  stalk-borer  is  credited  with  doing  injury  to 
the  stalks  of  tomato,  potato,  spinach,  cauliflower,  eggplant,  pep- 
per,  dahlia,   aster,   lily,   spirsea   and   salvia;   and   to   the   twigs 


Fig.  127.— Common  stalk-borer,  a,  Female  moth;  b,  half-grown  larva;  c,  mature  larva 
in  Injured  stalk,  d,  abdominal  segment  of  same;  e,  pupa.  All  somewhat  enlarged. 
(Author's  illustration,  U-  S.  Dept.  Agr.) 


of  blackberry,  currant,  apple  and  peach,  as  well  as  to  the  stems 
and  stalks  of  wheat  and  corn. 

When  the  borer  infests  the  crop  plants  that  have  been 
enumerated  the  portions  above  the  point  of  attack  in  the  stem 
wilts  and  finally  withers  before  breaking  down.  In  the  case 
of  infestation  to  such  rank-growing  vegetation  as  ragweed 
{Ambrosia  triMa),  cocklebur  and  the  like,  several  larvae  of  this, 
as  well  as  other,  species  may  be  present  without  seeming  harm  to 
the  weed's  growth.  In  large  stems  the  larva  normally  passes  its 
entire  existence  in  a  single  plant,  but  when  small  grains  are 
attacked  it  deserts  one  for  another. 


INSECTS  INJURIOUS  TO  SWEET   CORN  201 

The  different  species  of  this  genus  of  which  there  are  many 
seem  to  agree  in  transformation  to  pupse  in  the  larval  burrow, 
the  last  act  of  the  larva  before  making  its  final  moult  being 
the  construction  of  a  large  opening  about  one-fourth  inch  in 
diameter  for  its  escape  when  the  moth  condition  is  attained. 
The  pupal  period  lasts  from  two  to  four  weeks  and  the  moths 
issue  sometime  in  September  or  October. 

Remedies. — In  ordinary  cases  this  stalk-borer  can  be  held  in 
check  in  the  small  vegetable  garden  which  it  has  invaded  by 
pulling  and  burning  infested  plants.  As  the  moth  lays  her  eggs 
on  the  stems  in  September,  fall  plowing  is  advisable,  or  raking 
up   and   burning   all    forms   of   vegetation,    especially   ragweed. 

In  large  fields  it  is  difficult  to  combat,  but  its  injuries  may  be 
prevented  by  care  in  keeping  down,  and  by  promptly  destroying, 
the  weeds  after  they  are  pulled  or  hoed  out  during  the  .growing 
season.  If  weeds  are  left  to  dry  the  striped  caterpillar  of  this 
species  will  desert  them  and  enter  cultivated  plants.  Crop  rota- 
tion is  advisable  where  this  can  be  conveniently  practiced,  and 
such  plants  as  cabbage,  radish  and  the  like,  onions,  beets, 
asparagus  and'  celery  are  suggested  as  alternates.  When  the 
plants  are  sprayed  with  arsenicals  for  other  insects  this  will 
operate  to  a  certain  extent  against  this  stalk-borer. 

Owing  to  the  frequency  of  attack  on  the  borders  of  culti- 
vated fields,  it  might  be  found  a  measure  of  some  value  to  per- 
mit the  ragweed  to  grow  at  these  points  as  lures  to  the  in- 
sects, and  destroy  them  before  September,  i.  c,  before  the  moths 
have  issued  to  lay  their  eggs  for  another  generation.  Fall 
plowing  should  be  practiced  or  the  fields  burned  over  late  to  de- 
stroy the  eggs. 

The  Larger  Corn  Stalk-borer  {Diatrcea  saccharalis  Fab.). — 
This  pernicious  corn  pest,  although  a  southern  insect,  in  a 
succession  of  seasons  which  favor  its  development  sometimes 
works  northward  as  far  as  Delaware  and  New  Jersey,  where  it 
is  occasionally-injurious,  and  westward  to  Kansas.   It  is  identical 


202  INSECTS    INJURIOUS    TO   VEGETABLES 

with  the  sugar-cane  borer  of  the  South.  In  seasons  of 
abundance  a  loss  of  25  to  50  per  cent  of  the  crop  is  not  un- 
usual. Sometimes  a  stalk  contains  as  many  as  30  or  more 
holes  drilled  by  this  borer.  In  addition  to  corn  and  sugar-cane, 
the  borer  has  been  noticed  on  sorghum  and  gama  or  sesame 
grass. 

The  moth  or  parent  of  this  stalk-borer  is  extremely  variable 
as  regards  size  and  markings.  There  is  an  individual  variation 
from  an  inch  to  nearly  an  inch  and  a  half  in  wing  expanse. 


Fig-  128.— Larger  corn  stalk-borer,    a,  Female  moth;  b,  wings  of  male;  c,  pupa;  d,  e,f, 
larvae.    Near  natural  size.    (After  Howard,  U.  S.  Dept.  Agr.) 

The  fore-wings  are  pale  ochreous  with  fine  darker  longitudinal 
lines,  with  a  discal  dot  and  marginal  ones  arranged  as  shown 
(fig.  128,  a,  b)  in  the  illustration.  The  larva  when  full  grown 
measures  three-fourths  of  an  inch  or  a  little  longer.  Some 
are  white  and  some  strongly  marked  with  black  or  brown 
arranged  in  round  and  elongate  spots.  This  variation  is  well 
shown  in  figures  d,  e,  and  /. 

Dr.  L.  O.  Howard  was  the  first  person  to  investigate  the 
habits  of  this  insect  in  the  United  States.  The  moths  appear 
in  spring,  and  soon  after  young  corn  comes  up  lay  eggs  on  the 
leaves  near  the  axils,  and  the  borers  on  hatching  penetrate 
the  stalks  near  the  joint,  tunnelling  usually  upward  through  the 
pith.  The  borer  grows  rapidly,  and  frequently  leaves  a  stalk 
at  one  place  and  enters  at  another,  making  several  holes  in  the 


INSECTS  INJURIOUS  TO  SWEET  CORN 


203 


course  of  its  lifetime.  When  full  fed  it  penetrates  to  the  outer 
surface  of  the  stalk  and  makes  a  hole  from  which  in  due 
time  it  issues  as  a  moth.  Figure  129,  a.  shows  a  stalk  infested 
by  the  first  generation  of  borers,  and  b  a  stalk  cut  open  to 
show  the  larval  burrow  in   which  the  pupa  is  resting.     The 


Fig.  129.— (7,  Stalk  infested  by  first  generation  of  borers;  b,  stalk  cut  open  (redrawn) 


pupa  state  is  assumed  in  Virginia  from  the  middle  of  July  on, 
and  the  moths  issue  ten  days  to  two  weeks  later.  The  eggs 
for  the  second  generation  are  deposited  soon  afterwards  on 
higher  grown  stalks,  and  the  larvae  are  mature  by  harvest  time. 
The  injury  accomplished  by  the  second  generation  consists 
largely  in  the  weakening  of  the  stalk  so  that  it  is  readily  blown 
down  by  winds,  whereas  damage  by  the  earlier  generation  pre- 


204  INSECTS    INJURIOUS   TO   VEGETABLES 

vents  the  maturing  of  the  ears.  The  borers  of  the  second  gen- 
eration (most  of  them)  pass  the  winter  as  larvae.  The 
periods  of  this  species  in  a  given  locality  are  tolerably  regular, 
hence  it  follows  that  early  corn  is  more  frequently  infested 
than  later  plantings,  and  corn  planted  after  the  first  of  June 
is  less  apt  to  be  seriously  infested.  Fortunately  severe  cold 
spells  kill  off  the  insect  from  time  to  time  in  the  North,  and 
the  writer  has  seen  corn  fields  practically  ruined  and  a  year 
or  two  later  has  been  unable,  after  hours  of  search,  to  find  more 
than  one  or  two  individuals  on  the  same  farms. 

Remedies. — If  planters  would  be  more  careful  in  methods 
of  cultivation  this  corn  stalk-borer  would  have  no  chance  to 
propagate  in  the  North.  In  regions  infested  by  this  insect 
corn  should  not  be  planted  until  after  the  first  of  June.  Strip- 
ping or  pulling  corn  for  fodder,  so  prevalent  in  the  South, 
and  leaving  the  bare  stalk  with  ear  attached,  is  a  bad  practice, 
not  alone  on  account  of  this,  but  other  insects,  and  should 
be  discontinued.  Treating  of  the  species  only  as  a  sugar-corn 
pest,  it  should  be  stated  that  the  same  remedies  should  be  prac- 
ticed on  field  corn,  sugar-cane  and  sorghum  to  prevent  the 
insect  spreading  from  one  field  to  another.  Butts  of  corn 
should  not  be  left  in  the  field  after  harvest,  as  they  afford  safe 
places  for  larval  hibernation,  but  should  be  dragged  off  and 
burned  as  promptly  as  possible. 

Rotation  of  crops,  if  practiced  over  considerable  areas, 
would  greatly  diminish  the  numbers  of  this  pest,  and  if  pursued 
in  connection  with  clean  farming  severe  losses  would  be  averted. 
Observation  has  shown  that  the  average  damage  to  crops 
planted  upon  land  which  was  in  corn  the  previous  year  reached 
25  per  cent,  while  the  average  to  corn  planted  on  sod  land  was 
only  10  per  cent,  even  where  this  land  was  close  to  former 
corn  land. 

The  Smaller  Corn  Stalk-borer  {Elasmopalpus  Ugnosellus 
Zell.).^ — This  stalk-borer  was  first  observed  depredating  on  corn 


INSECTS  INJURIOUS  TO  SWEET   CORN 


205 


in  the  Southern  States  not  earlier  than  1878,  and  years  later 
injurious  occurrences  in  stems  of  beans  and  peanuts  were 
reported.  The  moth  is  exceedingly  variable.  The  fore-wings 
are  pale  yellow  or  ochreous,  and  the  outer  border,  toward  the 
ends,  consists  of  dark,  purplish  scales.  The  female  (b)  has 
fore-wings    varying    from    reddish    to    nearly    black    and    the 


Fig.  130.— Smaller  corn  stalk-borer,  a,  Male  moth;  b,  fore-wing  of  dark  female;  bb, 
antenna  of  female;  c,  male  at  rest;  d,  larva;  e,  ventral  segment  of  larva  from  side, 
much  enlarged:  /,  cocoon.  All  except  e  three  times  natural  size.  (Author's  illustra- 
tion, U.S.  Dept.  Agr.) 

hind-wings  transparent,  silvery  fuscous.  The  larva  (fig.  130,  d) 
is  half  an  inch  or  more  in  length  when  mature,  and  a  most 
beautiful  object  when  viewed  through  the  lens;  pale  green, 
marked  with  nine  reddish  brown  longitudinal  stripes,  arranged 
in  transverse  bands.  Transformation  takes  place  in  a  cocoon 
formed  of  sand  or  dirt  (fig.  130,/).^ 

This  is  a  tropical  species,  occurring  from  the  Gulf  as  far 
north  as  North  Carolina.  It  also  inhabits  Central  and  South 
America. 

"While    chiefly    injurious    to    young    corn,    destroying    many 

1  A  full  account  of  this  species  is  given  in  Bui.  23,  Bu.  Entom.,  U.  S.  Dept, 
Agr.,  pp.  17-22. 


206  INSECTS    INJURIOUS    TO    VEGETABLES 

Stalks  and  necessitating  the  replanting  of  many  hills,  the  smaller 
stalk-boper  works  throughout  the  entire  summer  and  fall,  and, 
as  late  as  October,  cuts  the  toughened  stalks  of  the  late  corn 
to  such  an  extent  that  they  are  easily  blown  to  the  ground,  and 
the  ears  are  often  rendered  useless  by  contact  with  the  wet 
earth.  The  principal  work  of 
the  borers  is  done  at  the  surface 
of  the  ground,  although  they  are 
often  found  just  above  or  below 
this  point." 

Injury  to  the  root  stalk  ex- 
tends, occasionally,  to  the  depth 
of  two  inches.  In  attack  on  beans 
the  larvae  also  work  in  the  earth, 
holes  showing  where  they  force 
out  their  excrement  or  make  their 
escape.  In  one  case  of  infesta- 
tion upwards  of  90  per  cent,  of  a 
planting  was  destroyed.  Where 
peanuts  have  been  injured,  as 
much  as  half  a  crop  was  de- 
stroyed, the  larvae  sometimes  pen- 
etrating the  shells  of  the  tubers. 
When  about  to  transform,  this 
borer  leaves  the  stalk  and  spins 

Fig.    131. -Cornstalk  showing  work  of   ^^    ^^^1      SOmewhat    flattened    co- 
smaller  corn  stalk-borer.    Natural  size. 

(After  Riley,  u.  s.  Dept.  Agr.)  coon,     which     becomes     covered 

with  earth  or  excremental  pellets. 
Remedies. — As  this  stalk-borer  hibernates  in  all  stages — larva, 
pupa  and  adult — a  practical  remedy  is  difficult  to  find.  The 
pulling  up  and  burning  of  infested  material  as  early  as  possible 
after  the  crop  is  removed,  and  rotation  with  some  crop  that 
would  not  be  affected  by  this  species,  are  desirable.  The 
smaller  cereals,  sweet  potato,  cotton,  cucurbits,  potato,  tobacco 


INSECTS  INJURIOUS  TO  SWEET   CORN  20/ 

and  asparagus  are  suggested  as  alternate  crops.  It  does  not 
seem  possible  that  the  insect  could  be  reached  with  insecticides 
with  profit.  Kerosene  emulsion  or  bisulphid  of  carbon,  how- 
ever, should  be  tried. 

This  brings  us  to  the  subject  of  the  insects  injurious  to  the 
ears.     Of  these  the  corn-ear  worm  is  the  most  important. 

The  Corn-ear  Worm  {Helio- 
this  obsolcta  Haw.). — The 
maturing  ears  of  corn  and 
pods  of  beans  and  cowpeas  are 
often  found  bored  full  of  holes 
and  the  seed  within  devoured. 
The  insect  most  often  con- 
cerned in  damage  of  this  na- 
ture is  figured  herewith.  It  is 
a  well  known  enehiy  of  corn, 
cotton  and  tomatoes,  whence 
it  has  received  the  vernacular 
names  corn-ear  worm,  boll- 
worm,  and  tomato  fruit  worm. 
It  is  a  species  of  wide  distribu- 
tion and  destructiveness,  but 
whether  indigenous  to  this 
country    or    imported    is    not 

known.        In     addition     to     the   F'S   1 32 —Corn-ear  worm  (//e/zo/tooiso/e/a 
...  .  Haw )  and  characteristic  injury  to  ear  of 

crops    mentioned,    this    species       ^,,„.  (Ouamtance,  U.  S.  Dept.  Agr.) 

injures       tobacco.       pumpkin, 

squash,  melon,  pepper,  okra  and  other  vegetables.  Even  if  only 
a  single  hole  is  made  in  an  ear  of  corn,  the  damage  is  apt  to  be 
considerable,  as  the  remainder  is  likely  to  become  more  or  less 
decomposed  and  access  is  afforded  to  other  insects  and  to  rain. 
The  same  is  true  of  the  injuries  by  this  insect  to  other  fruits, 
to  tomatoes,  beans,  etc. 
The  adult  moth  is  ocher  yellow,  more  or  less  variegated  with 


208 


INSECTS    INJURIOUS   TO   VEGETABLES 


blackish  markings,  and  arranged  as  in  figure  1320:,  a.  It  meas- 
ures about  an  inch  and  a  half  across  its  expanded  fore-wings. 
The  ear  worm  itself  varies  greatly  in  color,  different  shades  of 


pink,    purple    and   green   prevailing, 
shown  at  b. 


A   dark   striped    form   is 


Injury  to  young  corn 
by  the  first  genera- 
tion is  confined  largely 
to  the  ''bud,"  and  be- 
comes apparent  as 
the  ragged  or  shot- 
holed  leaves  unfold. 
It  is  rarely  serious  in 
extent.  Likewise,  in- 
jury by  the  second 
generation  is  compar- 
atively insignificant, 
but  the  third  genera- 
tion, affecting  roast- 
ing ears,  may  be  the 
cause  of  much  loss. 
Remedies. — No  practical  means,  aside  from  farming  methods, 
such  as  late  fall  or  winter  plowing,  and  judicious  rotation  of 
crops,  have,  as  yet,  been  discovered  for  reducing  injury  to 
corn.  The  remedy  which  gives  most  promise  of  controlling 
this  pest  farther  north  consists  in  planting,  where  weather  con- 
ditions permit,  several  days  earlier  than  customary,  and  taking 
chances  on  the  weather  which  may  follow.  A  few  days'  differ- 
ence may  save  considerable  corn.  In  any  case,  it  is  advisable 
to  plant  as  early  as  possible,  since,  as  a  rule,  the  later  the  corn 
is  planted  the  more  injury  by  the  ear  worm. 

The  Fall  Army  Worm  (Laphygma  frugiperda  S.  &  A.). — 
If  it  were  not  for  its  extreme  periodicity  of  attack  the  fall 
army  worm  would  rank  high  as  a  corn  pest,  as  it  affects  not 


Fig.  132x.— Corn-ear  worm,  a,  Moth;  b-,  larva 
(Author's  illustration,  U.  S.  Dept.  Agr.) 


INSECTS  INJURIOUS  TO  SWEET  CORN 


209 


only  the  foliage,  but  bores  into  the  ears  when  they  are  quite 
young,  destroying  them  utterly.  The  writer  has  seen  fields 
in  Virginia  badly  attacked  in  this  manner,  the  outward  appear- 
ance so  closely  simulating  that  due  to  the  corn-ear  worm  as  to 
deceive  all  who  witnessed  the  injury.  It  is  discussed  more 
fully  on  page  56  on  army  worms. 

The  Brown  Fruit-chafer  {Euphoria  inda  Linn.). — The  ears 
of  green  corn,  ripening  fruits  and  some  flowers  are  subject  to 
the  attack  of  the  stout  hairy  brown  beetle  figured  in  133.  The 
length  is  half  an  inch  or  more.  The  larva  (d)  is  a  white-grub, 
with  the  lower  moiety  of  the  body  of  a  dull  leaden  hue  from 
the  contents  of  the  abdomen.  Transformation  to  pupa  takes 
place  in  a  cocoon  smooth  within  and  irregular  on  the  outer 
surface.  This  species  occurs  practically  everywhere  in  the 
United  States  east  of  the  Rocky  Mountains. 


Fig.  133 —Brown  fruit-chafer,    a,  Beetle;  b.  egg;  c,  d,  larvae;  e.  pupa     All  enlarged 
(Author's  illustration,  U.  S.  Dept.  Agr.) 

Injury  is  confined  to  newly  transformed  beetles  in  autumn. 
The  food  of  the  larva  is  manure,  humus,  and  similar  material, 
and  not  healthy  roots,  as  once  supposed.  The  beetles  feed 
naturally  on  sap  exuding  from  wounds  in  trees,  and  juices  of 
overripe  or  injured  fruits  or  other  vegetable  growth,  and 
have  an  especial  fondness  for  ears  of  ripening  corn,  particularly 
sweet  corn,  and  even  bore  through  the  husks  to  the  kernels 
within.     The   beetles   devour   flowers   of   different    fruits,   and 


2IO  INSECTS   INJURIOUS   TO   VEGETABLES 

attack  fruit  exposed  for  drying.  The  large  size  of  these  beetles 
and  their  habit  of  assembling  in  numbers  render  them  at  times 
an  object  of  much  apprehension.  About  the  District  of  Colum- 
bia the  beetles  may  be  seen  in  April  flying  low,  with  a  loud 
humming  sound  like  a  bumblebee.  The  new  generation  begins 
to  appear  toward  the  end  of  August,  the  date  varying  with 
locality  and  season,  and  after  they  have  fed  for  two  or  three 
weeks  they  go  into  winter  quarters.  A  single  generation  is 
produced  in  a  year. 

Remedies. — Hand  methods  are  available  remedies  for  the 
beetles  when  they  occur  in  abundance.  The  use  of  insecticides 
on  ripening  fruit  is  practically  out  of  the  question.  During  the 
heat  of  the  day,  particularly  in  bright  sunlight,  the  beetles  are 
active,  but  in  the  shade  when  feeding  they  can  readily  be 
captured  by  jarring  them  from  the  plants  on  which  they  occur 
into  bags  or  nets.  Fortunately,  the  species  is  only  intermittently 
troublesome,  and  therefore  it  need  not  cause  serious  alarm. 

Cutworms  and  Other  Caterpillars. — The  fondness  of  cutworms 
for  young  corn  is  proverbial,  and  rarely  is  a  corn  field  entirely 
exempt  from  the  presence  of  these  ancient  foes  of  man.  Sweet 
corn  is  particularly  affected  by  these  ravagers,  but  as  a  rule, 
owing  to  the  later  planting  of  corn,  it  does  not  suffer  so 
great  injury  as  plants  that  are  reset  from  forcing  houses,  such 
as  tomato,  cabbage,  and  the  like.  Nearly  all  other  field  and 
garden  caterpillars,  including  the  fall  army  worm  and  garden 
webworm,  with  general  feeding  tendencies,  will  attack  corn 
when  more  preferred  plants  are  lacking. 

The  corn  cutworm  (Noctua  c-nigrum  Linn.)  better  known 
as  the  spotted  cutworm,  is  one  of  our  commonest  and  most 
destructive  species,  and  resembles  the  variegated  cutworm 
treated  on  pages  53  and  54,  being  cosmopolitan,  nearly  om- 
nivorous, a  climbing  species,  and  traveling  in  armies  like  the 
army  worm.  The  cutworm  (fig.  134,  b)  is  pale  brown  or  gray, 
sometimes   whitish,   with   green   or   olive   tints,   and   measures 


INSECTS    INJURIOUS    TO    SWEET   CORN 


211 


fully  about  an  inch  and  a  half.  The  moth  has  brown  fore- 
wings,  tinged  with  reddish  or  purplish,  and  marked  as  figured 
(fig.  134,  a).  In  addition  to  corn  and  cereals,  this  species 
affects  cabbage,  turnip,  pea,  carrot,  tomato,  celery,  rhubarb  and 
other  vegetables. 

Cutworm  remedies  are  discussed  on  page  54. 


Fig.  134.— Spotted  cutworm,    a,  Moth;  6.  larva.    Somewhat  enlarged 
(Author's  illustration) 

Flea-beetles. — A  considerable  number  of  flea-beetles  are  com- 
monly found  on  corn,  but  of  these  the  two  species  mentioned 
below  are  more  particularly  attached  to  this  crop.  All  species 
are  most  troublesome  on  young  plants. 

The  brassy  flea-beetle  (Chcctocnema  puli- 
caria  Mels.).  Injury  to  sweet  corn  by  flea- 
beetles  is  sometimes  complicated  by  the 
presence  of  two  species.  The  present  is 
the  more  abundant  of  the  two  in  most 
localities,  and  as  it  is  considerably  smaller, 
it  is  probable  that  it  is  usually  the  cause  of 
the  trouble  attributed  to  it.  It  measures 
less  than  one-twentieth  of  an  inch,  and  is 
of  oval,  convex  form,  with  shining  surface, 
having  a  faint  greenish-bronze  lustre.  The 
legs  are  usually  brownish  testaceous,  and 
the  thorax  bears  little  trace  of  polish  (fig.  135) 


Fig.  135.-Brassy  flea- 
beetle.  For  size  see  line 
at  right.  (Author's  illus- 
tration, U.S.Dept.Agr.) 


212 


[NSECTS    INJURIOUS   TO   VEGETABLES 


It  occurs  in  Pennsylvania,  Maryland,  Virginia,  District  of 
Columbia,  North  Carolina.  Texas  and  Colorado. 

The  toothed  flea-beetle  {Chcctocncma  denticnlafa)  resem- 
bles the  species  just  figured.  It  is,  however,  much  larger, 
measuring  fully  twice  as  long,  or  about  one-tenth  of  an  inch, 
is  more  robust,  somewhat  irregularly  oval,  the  entire  surface 
brightly  bronzed  and  slightly  brassy. 

It  is  distributed  from  New  England  to  Florida.  Texas  and 
Montana,  and  is  found  even  in  California. 

Remedies. — These  two  species  can  be  destroyed  by  arsenicals 
and  other  remedies  advised  in  the  discussion  of  flea-beetles 
(pages  65  and  66). 

Other  Insects. — For  a  consideration  of  other  insects  which 
injure  corn,  such  as  wireworms  and  white  grubs,  see  pages 
73  to  83. 

A  species  of  wireworm  common  in  the  corn  fields  of  the  South 
is  illustrated  in  its  several  stages  in  figure  135.^. 


Fig.  135x.— Southern  corn  wireworm  {Monocrepidius  vespertinus) .  a  b.  Larva,  c,  beetle; 
d,  pupa— about  three  and  one-half  times  natural  size.  (Author's  illustration,  U.  S. 
Dept.  Agr.) 


CHAPTER   XIII 

INSECTS  INJURIOUS  TO  POTATO  AND  SIMILAR 
VEGETABLES 

SoLANACEOUs  vegetables  include  potato,  tomato,  eggplant, 
pepper  and  cultivated  species  of  Physalis,  one  of  which  is 
known  as  husk  tomato.  A  moderate  number  of  insects  are 
attached  to  these  plants  and  most  of  them  affect  tobacco,  be- 
sides weeds  of  the  same  family. 

The  most  important  potato  insect  in  the  economic  sense,  is 
the  Colorado  potato  beetle,  followed  by  half  a  dozen  or  more 
destructive  blister  beetles,  and  less  important  species  of  the 
same  group.  Numerous  species  of  cutworms  select  the  tomato 
and  potato  as  their  particular  prey  and  the  latter  plant  is  favored 
by  several  forms  of  flea-beetles.  Among  other  insects  which 
take  their  name  from  the  potato  are  the  potato  stalk-weevil  and 
potato  stalk-borer,  potato  tuber  moth  and  potato  scab  gnat.  The 
two  species  last  mentioned  injure  particularly  the  stored 
product,  and  several  other  insects  attack  the  tubers  in  the 
ground.  Of  such  are  wireworms  and  certain  cutworms,  e.  g., 
the  variegated  cutworm,  when  they  become  unusually  numerous, 
and  white  grubs. 

All  of  the  general  feeders  which  have  been  mentioned  are 
Treated  in  introductory  chapters.  Some  of  the  blister  beetles, 
more  particularly  the  striped  blister  beetle,  are  known  as  old- 
fashioned  potato  beetles.  In  the  Southwest  there  are  numerous 
species  of  these  insects  which  affect  the  potato  crop  in  that 
section.  One  of  the  potato  stalk-borers  is  treated  under  the  name 
of  "the  common  stalk-borer"  in  the  chapter  on  corn  insects 
(page  199). 

az3 


214  INSECTS    INJURIOUS   TO   VEGETABLES 

Three  species  of  aphides  commonly  occur  on  potato  and  are 
apt  also  to  attack  tomato,  eggplant,  and  other  Solanacese.  The 
same  is  true  of  mealy-bugs.  The  aphides  include  the  common 
"green  fly,"  ^  "black  dolphin,"  "  and  "melon  louse."  "  Some  forms 
of  tree-hoppers  and  related  species,  and  thrips  also,  attack 
these   plants. 

The  Colorado  Potato  Beetle  {Lcptinotarsa  dcccmlincata  Say.). 
— Soon  after  the  Civil  War  the  Colorado  potato  beetle  created 
quite  as  great  consternation  as  the  San  Jose  scale  at  the  present 
time.  There  is  perhaps  no  more  familiar  insect  to  those  who 
live  a  rural  life,  and  every  country  boy  or  girl  knows  its  two 
active  stages.  It  is  still  one  of  our  worst  pests  owing  to 
the  fact  that  we  must  wage  more  or  less  perpetual  warfare  to 
suppress  it.  In  its  early  days  there  seemed  to  be  no  check  to 
its  increase,  but  in  the  course  of  years  many  natural  enemies 
have  learned  to  prey  upon  it,  until  in  many  localities  it  is 
largely  kept  in  abeyance  by  such  agencies.  It  is  of  peculiar 
interest  as  being  the  direct  cause  of  the  use  of  Paris  green 
upon  edible  plants.  Fortunately,  with  a  little  knowledge  of  the 
habits  of  this  insect,  the  use  of  arsenicals  and  the  friendly 
assistance  of  natural  enemies,  the  insect  can  now  be  held  in 
practical  subjection,  otherwise  it  would  be  one  of  the  greatest 
scourges  of  this  country. 

This  insect  is  so  well  known  that  a  description  is  hardly 
necessary,  but  that  there  may  be  no  danger  of  confusing  it 
with  blister  beetles  and  others  of  similar  habits,  with  which 
it  is  occasionally  associated,  a  few  words  of  description  may  be 
given.  The  beetle  is  of  the  robust  form  shown  in  figure  136, 
d,  d,  ochre  yellow  in  color,  with  the  wing-covers  ornamented 
with  ten  black  lines.  The  eggs  are  oval  and  orange  colored, 
and  are  deposited  in  masses  of  a  dozen  (a,  a)  or  more  on  the 
lower  surface  of  the  leaves.     The  larvae  or  "slugs"  {h,  h)   are 

^  Rhopalosiphum  dianthi  Schrk.       "Aphis  rumicis  L.       ^  Aphis  gossypii  Glov. 


INSECTS    INJURIOUS    TO    POTATO,    ETC.  215 

as  well  known  as  the  beetles.    They  are  soft,  slimy,  red-colored, 
evil-looking  creatures. 

The  Colorado  potato  beetle  was  first  associated  with  injury 
to  potato  in  1865,  prior  to  which  time  it  had  fed  on  the  sand 
bur.^  With  the  advance  of  civilization  westward  and  the  culti- 
vation of  potato  in  the  vicinity  of  its  native  home,  the  insect 


Fig.  136.— Colorado  potato  beetle,  aa,  Eggs;  bb,  larvae;  c,  pupa;  dd,  beetles— all  enlarged 
about  one-fourth;  e,  wing-cover— much  enlarged.    (After  Riley) 

acquired  the  habit  of  feeding  on  this  more  succulent  plant.  By 
1869  it  had  found  its  way  to  Ohio  and  the  year  following  was 
very  destructive  throughout  the  Northwest,  continuing  its 
eastward  march  at  an  increasing  rate. 

Since  that  time  its  migration  eastward,  northward  and  south- 
ward has  continued.  Its  progress  eastward  was  accomplished 
largely  by  flight,  as  the  writer  had  occasion  to  observe  when  a 
resident  of  Cleveland  in  the  early  days  of  its  invasion  of  the 
Buckeye  State.  With  outspread  wings  numerous  individuals 
could  be  seen  on  bright  days  in  spring  and  early  summer, 
being  carried  with  the  winds  directly  eastward.     By  the  cen- 

^S.  olanum  rostratum. 


2l6  INSECTS    INJURIOUS    TO   VEGETABLES 

tennial  year  the  Colorado  potato  beetle  occupied  an  area  com- 
posing more  than  a  third  of  the  United  States. 

Beetles  and  larvae  are  destructive  in  nearly  equal  proportion. 
In  its  early  occurrence  as  a  pest  it  not  only  caused  entire 
losses  of  crops,  but  sometimes  destroyed  the  potato  yield  of 
whole  counties,  and  large  portions  of  some  States.  Indeed, 
at  one  time  it  materially  affected  the  market  price  of  potatoes 
by  direct  depredations  and  in  discouraging  farmers  in  the 
cultivation  of  this  crop.  At  the  present  time  growers  recognize 
the  fact  that  the  control  of  the  potato  beetle  is  a  part  of  the 
routine  of  the  culture  of  this  tuber,  and  that  its  natural  enemies 
assist  in  a  remarkable  degree  in  reducing  its  numbers.  The 
insect  is  nearly  always  found  on  its  wild  plants  wherever  they 
Occur  and  it  practically  feeds  on  all  solanaceous  crops  and 
weeds,  including  tomato,  tobacco,  ground  cherry,  thorn  apple, 
and  Jamestown  weed,  henbane  (hyoscyamus),  belladonna, 
petunia,  and  Cayenne  pepper.  The  tender  leaved  varieties  of 
potato  are  most  affected,  while  those  with  less  tender  foliage, 
of  the  "Peach  Blow"  and  "Early  Rose"  type,  are  comparatively 
immune. 

The  beetle  hibernates  under  ground  and  is  credited  with 
being  double-brooded  with  sometimes  a  third  partial  generation, 
which  hibernates  in  the  pupal  condition.  The  beetles  appear 
early  in  spring,  issuing  soon  after  the  first  thawing  of  the 
ground,  at  this  season  flying  during  the  more  heated  portions 
of  warm  days,  making  aerial  journeys  of  considerable  extent. 
Larvae  hatch  in  from  less  than  a  week  to  a  little  later,  accord- 
ing to  the  prevailing  temperature,  and  in  two  or  three  weeks 
usually  acquire  maturity,  when  they  undergo  transformation  to 
pupae  and  subsequently  to  beetles  in  cells  which  the  larvae 
form  in  the  earth.  The  insect  is  to  be  found  in  practically 
all  stages  during  the  summer  months,  and  as  long  as  there  are 
suitable  plants  for  food.  A  single  female  is  capable  of  pro- 
ducing from  five  hundred  to  a  thousand  eggs.     The  entire  life 


INSECTS    INJURIOUS    TO    POTATO,    ETC.  21/ 

cycle  from  egg  to  adult  may  be  passed  in  a  single  month, 
and  the  last  generation  of  beetles  issues  early  in  autumn  and 
re-enters  the  earth  for  hibernation.  Fluctuation  in  numbers 
of  the  Colorado  beetle  is  noticeable  at  least  locally  every  sea- 
son, and  is  largely  attributable  to  the  activity  of  its  insect  ene- 
mies and  to  atmospheric  conditions.  Up- 
wards of  30  species  of  insects  prey  upon 
this  beetle.  One  of  the  most  important  of 
these  is  a  predaceous  ground-beetle,  Lebia 
grandis  Hentz  (fig.  137). 

Remedies. — No  other  methods  are  nec- 
essary than  the  free  use  of  Paris  green 
or  arsenate  of  lead  and  mechanical  means 
for  its  destruction. 

Hand-picking,  if  employed  early  in  the 
season,  is  of  great  value,  but  where  large   F's-   '37.  -  Lebia  granms. 

,  .        .  ,      ,  Enemy     of     tha      potato 

areas  are  planted  other  methods  are  nee-      beetle.   (Marxrfe/) 
essary.     Gathering  the   beetles   and  their 

larvae  in  pans  containing  a  little  water  on  which  a  little  kerosene 
is  floating,  is  an  effective  remedy.  Methods  of  preparing  and 
applying  the  arsenicals  are  given  in  the  chapter  on  insecticides. 

If  the  grower  can  secure  the  cooperation  of  his  neighbors  in 
the  destruction  of  this  pest,  and  will  also  kill  the  insects  on 
wild  plants,  much  can  be  done  toward  limiting  its  numbers  in 
small  areas.  It  seldom,  if  ever,  migrates  as  formerly,  and  there 
is  not  so  much  likelihood  of  reinfestation  from  a  distance.  It 
is  always  wisdom  to  keep  down  weeds,  and  in  the  treatment  of 
the  present  insect,  if  they  were  cut  before  seeding,  it  would 
serve  a  dual  purpose  in  preventing  the  increase  of  weed  as  well 
as  insect.  The  susceptibility  of  the  "slugs"  to  extreme  heat, 
indicates  that  the  remedy  for  the  asparagus  beetle  of  brushing 
them  from  the  plants  on  hot  dry  days  will  be  effective. 

The  Potato  Flea-beetle  (Epitrix  cuciimeris  Harr.). — Much 
injury  to  potato  is  inflicted  by  flea-beetles  which  attack  most 


2l8 


INSECTS    INJURIOUS    TO   VEGETABLES 


solanaceous  plants,  of  which  they  are  specific  enemies,  riddling 
the  leaves  with  punctures  and  causing  them  to  die,  thus  weak- 
ening the  vitality  of  the  plants,  while  the  larvK  of  some  of  them 
feed  at  the  roots  and  do  injury  in  this  manner.  The  most  im- 
portant of  these  insects  are  three  species  known  respectively 
as  the  potato,  the  eggplant  and  the  tobacco  flea-beetles,  their 
names  indicating  the  plants  which  they  most  often  injure. 
This  potato  flea-beetle  (fig.  138)  is  the  most  destructive  of 
this  group.     The  name  "cucumber  flea-beetle"  was  given  it  by 


Fig-  138.  — Potato  flea-bee'.lg. 
Much  enlarged.  (Author's  il- 
lustration, U.  S.  Dept.  Agr.) 


Fig.  139. —  Egg-plant  flea-beetle. 
Greatly  enlarged.  (Author's  il- 
lustration, U.  S.  Dept.  Agr.) 


Harris,  who  found  it  very  destructive  to  cucumber,  eating  the 
seed  leaves  and  destroying  the  plant.  It  is  very  minute,  meas- 
uring only  1/16  inch  in  length,  perfectly  black,  with  clay- 
yellow  antennae  and  legs,  and  there  is  a  deep  transverse  furrow 
at  the  base  of  the  thorax.  This  species  is  generally  known 
from  Massachusetts  to  Georgia,  and  westward  to  California. 

Injuries  are  most  apparent,  however,  in  the  North.  The 
larva  is  confined  to  solanaceous  plants  for  food,  and  is  the  cause 
of  "pimply"  potatoes.  When  this  trouble  attracted  attention 
in  New  York  in  1894,  potato  buyers  were  on  the  lookout  for 
potatoes  so  affected,  offering  a  reduced  price  for  them.  Fre- 
quently such  sold  for  five  cents  a  bushel  below  the  regular 
market  price.     The  so-called   "pimples"  were  accompanied  by 


INSECTS    INJURIOUS    TO    POTATO,    ETC.  219 

"slivers,"  and  it  was  some  time  before  it  was  ascertained  that 
they  were  due  to  the  slender  white  grubs  of  this  flea-beetle. 
Eggplant,  tobacco  and  tomato  are  affected  less  as  a  rulfe  than 
potato,  but  the  beetles  also  attack  plants  of  other  orders,  inclu- 
ding beets,  cabbage,  turnip,  cucumber,  celery  and  sweet  potato. 
Sometimes  they  do  injury  to  potatoes  by  gnawing  the  sprouts. 
Eggs  are  deposited  in  May  or  June,  and  the  life  cycle  is  very 
like  that  of  the  tobacco  flea-beetle  about  to  be  described.  Larvae 
feed  entirely  under  ground  and  transform  to  pupae  there. 

Treatment. — The  usual  flea-beetle  remedies  are  applicable. 
See  page  65. 

The  Eggplant  Flea-beetle  (Epitrix  fuscula  Cr.).— The  egg- 
plant flea-beetle  so  nearly  resembles  the  preceding  that  unless 
the  two  occur  on  the  same  plant  they  are  apt  to  be  confounded. 
It  is  of  the  same  color,  but  considerably  larger  than  the  potato 
flea-beetle,  and  when  closely  examined  it  is  at  once  seen  that 
the  impression  at  the  base  of  the  thorax  is  very  feeble  and 
that  the  wing-covers  are  more  pubescent. 

This  species  is  most  abundant  on  eggplant,  but  it  is  common 
on  potato,  horse  nettle  and  similar  wild  plants.  In  Maryland, 
Virginia  and  the  District  of  Columbia  it  is  often  difficult  to 
find  the  foliage  of  eggplant  that  has  not  been  very  profusely 
punctured  by  the  minute  holes  where  the  beetle  has  been  feed- 
ing. Some  little  time  after  attack  these  holes  become  browner 
on  the  edges,  and  this  portion  at  last  dries,  making  the  holes 
much  larger  and  giving  the  plants  a  decidedly  sickly  appearance. 
It  even  attacks  eggplant  in  frames.  This  species  is  obviously 
southern,  not  extending  in  the  East,  so  far  as  known,  north 
of  New  Jersey.  It  occurs  in  the  Gulf  region  and  in  southern 
Ohio  and  Illinois,  and  in  intermediate   States  southward. 

Remedies. — The  same  as  those  employed  against  other  flea- 
beetles. 

The  Tobacco  Flea-beetle  {Epitrix  parvula  Fab.). — This 
species    is    most    important    as    an   enemy    of    tobacco,    and    like 


INSECTS    INJURIOUS    TO   VEGETABLES 


the  preceding  is  commonest  southward.  Where  occurring  nor- 
mally it  is  often  found  in  about  the  same  abundance  on  potato, 
eggplant,  tomato,  horse-nettle,  night-shade  and  Jamestown  weed. 
The  plants  mentioned  are  sometimes  damaged  and  its  work  is 
evident  on  these  crops  from  Maryland  and  Virginia  southward. 
■The  beetle  is  scarcely  more  than  one-twentieth  of  an  inch 
long,  pale  brown   in   color,  the  elytra  being  normally  marked 

near  the  middle  with  a 
dark,  transverse  band  of 
greater  or  less  extent 
(fig.  140,  (7).  The  larva 
(b)  is  delicate,  thread- 
like and  white,  except 
the  head,  which  is  yel- 
low. The  beetle  riddles 
leaves  in  the  same  man- 
ner as  do  other  flea- 
beetles,  and  in  its  attack 
on  tobacco  frequently 
renders  plants  unfit   for 

Fig.   140.— Tobacco  floa-beetle,    a,  Beetle:  i,  larva;   use.        It     is     doubtleSS     3. 
c,  head  of  larva;  d,  posterier  leg;  e,  anal  segment; 

/,  pupa,  a,  b,  f,  Enlarged  about  fifteen  times;  transmitter  of  certam 
c,  rf,  e,  more  enlarged.  (Author's  illustration,  U.  S.  diseases,  which  form  a- 
Dept.  Agr.)  ,  '  , 

bout  the  punctures  made 
by  the  beetle  in  obtaining  its  food  supply.  From  experiments 
by  the  writer  it  has  been  learned  that  the  full  life  cycle  may  be 
passed,  'in  extremely  hot  weather,  in  28  days.  The  egg  period 
in  such  weather  is  about  six  days,  the  pupa  is  the  same,  which 
affords,  by  deduction,  a  larval  period  of  16  days. 

Remedies  are  discussed  on  page  65,  on  the  flea-beetles. 

The  Black  Blister  Beetle  (Epicauta  pennsylvanica  DeG.). — 
The  farmer  is  quite  too  well  acquainted  with  this  and  other 
blister  beetles  as  unwelcome  visitors  to  his  potato  patch,  and 
florists  know   it  as  the  "aster  bug,"   from  the   severe   injuries 


INSECTS    INJURIOUS    TO    POTATO,    ETC.  221 

which  it  does  to  asters  and  related  plants.  It  is  uniformly 
black,  without  polish,  and  its  length  varies  from  a  little  more 
than  a  quarter  to  half  an  inch.  It  is 
well  distributed  east  of  the  Rocky 
Mountains,  and  does  most  injury  be- 
tween the  Atlantic  States  and  Texas. 
Its  time  of  appearance  is  more  or  less 
coincident  with  the  blossoming  of  the 
goldenrod,  on  which  it  is  a  familiar 
object,  from  June  until  October.  As 
a  rule  it  appears  later  than  other ' 
species.  It  is  one  of  the  worst  insect 
enemies  of  potato  and  beet,  and  is 
also  destructive  to  carrots,  beans,  cab- 
bage,   corn,    mustard,    aster,    clematis  F'g-    I4i.-Biack  Mister  beetle. 

Enlarged.  (Author's  illustration, 

and   other  plants.     For   remedies   see     u.  s.  Dept.  Agr.) 
page  68. 

The  Potato  Stalk  Weevil  (Trichobaris  trinotata  Say.). — This 
is  an  important  insect  enemy  of  the  potato,  and  a  common 
species  almost  everywhere  east  of  the  Rocky  Mountains  and 
south  of  New  England.  Its  larva  works  normally  in  the  stems 
of  horse  nettle,  ground  cherry,  and  jimson  weed,  in  most  fields 
where  these  plants  are  allowed  to  grow. 

The  habit  of  this  insect  of  attacking  potato  has  been  known 
since  1849.  Since  then  injuries  inflicted  by  it  have  attracted 
considerable  attention,  periodically  and  locally,  and  there  is 
reason  to  believe  that  it  is  often  present  and  doing  damage, 
though  undetected,  in  potato  fields,  where  the  insect  itself  has 
never  been  seen.  Its  habit  of  living  in  the  stem  in  its  larval 
condition,  and  the  small  size  of  the  beetles,  together  with 
their  trick  of  dropping  from  the  plants  when  disturbed,  is 
accountable  for  injury  so  often  escaping  notice. 

The  potato  stalk  weevil  (fig.  142)  is  a  small  snout-beetle, 
about  1/6  inch  in  length.     Its  real  color  is  black  throughout. 


INSECTS    INJURIOUS    TO   VEGETABLES 


but  its  surface  is  covered  with  minute  gray  scales,  which  give 
it  a  nearly  uniform  gray  appearance.  The  head,  however,  is 
black,  and  there  are  three  black  impressed  spots  at  the  base 
of  the  wing-covers.     The  snout  is  robust  and   rather  strongly 

curved.  The  northern  limit 
of  injurious  occurrence  of  the 
potato  stalk  weevil  is  reached 
in  Pennsylvania  and  New 
Jersey  in  the  East,  and  in  Il- 
linois and  Iowa  in  the  West ; 
recently,  however,  the  species 
has  been  reported  a  pest  in 
Canada.  Southward  the  insect 
is  found  to  Florida  and  Texas. 
More  often  perhaps  than 
not,  injury  by  this  pest  is  at- 
tributed to  drought  or  blight. 
Fig.  142.— Potato  stalk  weevil,    a.  Beetle;  It  is  more  conspicuous  in  sea- 

b,  larva;  c,  pupa;  a',  section  of  potato  stalk  r  i  j   j  ,  ^  j 

opened  to  show    larva  and   pupa  in   sffu.   ^0"^   ^^  prolonged  drought  and 

a,  b,  c.  Five  times  natural  size;  d,  natural  most  Severe  On  early  varieties 

size.    (Author's  illustration,   U.   S.    Dept.       r       ^    ^        t^i  j  •    •  r 

^  ^^  of  potato.    The  undermmmg  of 

the  stalks  by  the  larvae  causes 
them  to  wilt,  and  the  wilting  and  the  dying  of  the  leaves  is  the 
first  outward  manifestation  of  attack.  When  the  insects  are 
present  in  the  field  it  is  often  stated  that  the  plants  are  "blighted." 
The  diseases  of  potato  are  apt  also  to  be  mistaken  for  the  work 
of  the  weevil,  as  in  both  cases  the  leaves  look  as  if  sunburned, 
especially  after  the  vines  have  been  aflfected  for  some  time.  Not 
infrequently  a  field  suffers  from  the  combined  effects  of  dry 
weather,  disease,  and  stalk"  weevil. 

This  insect  attacks  nearly  all  Solanacese  growing  within  its 
natural  range.  The  list  includes,  besides  potato,  eggplant,  horse 
nettle,  bull  nettle,  jimson  weed,  purple  thorn  apple,  ground 
cherry  and,  it  is  said,  cocklebur. 


INSECTS    INJURIOUS    TO    POTATO,    ETC.  223 

A  single  larva  in  a  potato  stalk  is  not  sufficient  to  injure 
it  to  any  extent,  although  it  must  have  a  weakening  effect,  but 
when  many  larvae  occur  destruction  is  complete.  As  many  as 
5  or  6  individuals  may  sometimes  be  found  in  a  potato  stalk. 

The  beetles  appear,  in  the  vicinity  of  the  District  of  Colum- 
bia, in  the  latter  portion  of  May,  and  the  female  deposits  her 
eggs  singly  in  small  slits  about  one-twelfth  of  an  inch  in  length 
made  in  the  stalks  of  the  insect's  food  plants,  and  occasionally 
in  the  branches.  In  a  week  or  ten  days  the  larva  hatches, 
and  feeds  by  making  small  channels  which  increase  in  size  with 


Fig.  \4-3.—Si§alphus  curculionis-     Parasite  of  potato  stalk  weevil.     (After  Riley) 

the  growth  of  the  insect  downward  toward  the  bases  of  the 
stalks.  The  undermining  of  a  stalk  by  the  tunneling  of  several 
larvae  has  the  effect  of  impairing  the  vitality  of  the  plant  and 
causing  the  leaves  to  wilt  and  die.  Upon  attaining  full  growth 
the  larva  makes  a  cell  of  castings  and  woody  fibers  in  which  to 
transform.  The  beetles  of  the  new  generation  appear  as  early 
as  July  24.  In  northern  localities  development  is  slower,  the 
beetles  seldom  appearing  before  August  and  maturing  as  late 
as  September,  and  hibernation  is  always  as  a  beetle.  The 
knowledge  of  this  fact  is  of  value  in  the  control  of  the  species, 
as   will   be  explained. 


224  INSECTS    INJURIOUS   TO   VEGETABLES 

This  weevil  is  subject  to  the  attack  of  a  small  four-winged 
parasitic  ichneumon  fly,  Sigalpliiis  curculionis  Fitch  (fig.  143), 
a  well-known  enemy  of  the  plum  curculio,  and  sometimes  it 
falls  a  prey  to  wireworms. 

Remedies. — The  best  remedy  is  to  pull  infested  vines  as  soon 
as  they  wilt  and  show  evidence  of  attack,  and  spread  them  out 
so  that  they  will  be  exposed  to  the  sun  and  will  dry  and  thus 
prevent  the  escape  of  the  insects  which  they  contain.  All  stalks 
in  infested  fields  should  be  burned  as  soon  as  the  crop  is  off. 
This  will  greatly  lessen  the  number  of  weevils  for  the  ensuing 
years.  It  is  also  advisable  to  keep  down  all  solanaceous  weeds. 
The  time  for  their  destruction  is  in  July,  after  they  have  at- 
tracted the  beetles  for  G^gg  laying,  or  any  time  before  the  seeds 
are  ripe.  The  use  of  fertilizers  will  often  aid.  injured  plants  to 
recuperate  from  attack.  Unfortunately,  injury  is  not  apt  to  be 
detected  until  the  plants  begin  to  die.  As  soon,  therefore,  as 
a  plant  shows  weakness  its  stalk  should  be  split  open  to  ascertain 
the  cause.  Early  potatoes  are  most  subject  to  injury,  and  the 
latest  varieties  are  practically  exempt. 

The  Potato  Tuber  Worm  (PhthoriuKra  opcrculclla  Zell.). — 
The  tuber  worm  is  probably  the  most  injurious  insect  to  the 
truck  industry  of  California,  where  losses  to  the  potato  crop 
have  been  estimated  as  aggregating  some  years  25  per  cent.  In 
Salinas  Valley,  dealers  claim  that  at  times  the  loss  has  gone 
as  high  as  40,000  sacks  a  year.  Potatoes  from  other  sections 
have  to  be  watched  carefully  to  •  avoid  "wormy"  ones,  as  a 
very  few  such  may  infest  a  whole  storeroom.  As  the  potato 
is  a  product  that  is  expected  to  retain  its  value  for  months,  the 
possibility  of  destruction  by  insects  while  in  store  becomes  a 
question  of  great  seriousness,  more  particularly  because  rots 
follow  the  "worm,"  starting  in  its  burrow  and  ultimately  in- 
volving the  entire  tuber.  Although  the  species  is  introduced 
and  rather  commonly  distributed  in  temperate  portions  of  the 


INSECTS    INJURIOUS    TO    POTATO,    ETC. 


225 


United  States,  injury  to  potato  is  nearly  confined  to  California, 
although  tobacco  is  attacked  in  the  South  where  the  insect  is 
known  as  the  tobacco  leaf-miner  or  split-worm.  It  is  probable 
that  this  insect  may  in  time  become  a  pest  in  other  regions, 
though  not  in  the  colder  temperature  States. 

The  moth  (fig.  144)  resembles  a  clothes-moth,  but  is  darker. 
The  wing  expanse  varies  from  ^  to  about  %  of  an  inch.  The 
fore-wings  are  mottled  with  dark 
brown  and  black,  and  the  hind- 
wings  are  narrow,  with  long 
fringes.  Eggs  are  deposited  on 
the  leaves,  and  the  minute  worms 
(&,  c)  hatching  from  them  bur- 
row into  the  stems  and  afterward 
into  the  potato  tubers.  Fre- 
quently early  injury  is  done  to 
plants  in  the  field,  but  as  the 
larvae  grow  they  work,  later  in 
the  season,  farther  into  the  stems, 
and  when  these 
their  way  to  the  tubers  and  finish 


<ssmmmm» 


harden     make   Fig.  144— Potato  tuber  worm,  ff.  Moth; 
b,  c,  larva  or  "worm"  ;  d,  pupa;  e.  /, 
abdominal    segments    of    larva,      a-d, 
their    growth    there.       The    potato       Three   times  natural   size:   e,  /,  more 

is  subject  to  infestation  through-      l""'^',^"^-   <'"^^=^  ^'f^'  "•  ^    Dept. 

••  ^  Agr.) 

out  the  year,  provided  the  tubers 

are  stored  in  places  that  are  not  too  cold  for  the  insect's  devel- 
opment. The  life  cycle,  according  to  the  studies  of  Mr.  W.  T. 
Clarke,  may  be  accomplished  in  nine  weeks,  and  in  the  winter,  in 
the  mild  climate  of  California,  this  period  is  sometimes  run  in 
twelve  weeks.  When  the  larva  is  about  six  weeks  of  age  it 
comes  to  the  surface  and  transforms  to  pupa  at  the  mouth  of 
its  burrow,  or  seeks  a  crack  or  depression  in  the  potato  when 
the  tubers  are  stored.  The  usual  course  of  the  tuber  worm  is  to 
mine  beneath  the  outer  skin  of  the  plant,  and  molds  and  rots 
(bacterial  and  fungous  growths)    follow  in  its  wake,  the  stalk 


226  INSECTS    INJURIOUS   TO   VEGETABLES 

finally  succumbing  to  the  combined  injuries  of  insects  and  dis- 
ease. Injury  is  three-fold  to  the  plants  above  ground,  and  to 
the  tubers  in  the  field,  and  again  in  store.  The  moths  oviposit 
on  any  part  of  a  plant,  on  leaves,  stems,  on  tubers  in  the  hill  and 
when  exposed  in  the  field  and  after  they  are  stored. 

Methods  of  Control. — It  is  impossible  to  reach  the  tuber 
worms  in  their  mines,  in  stalks  or  tubers  growing  in  the  field, 
therefore  we  must  proceed  against  this  pest  in  other  ways. 
Several  must  be  employed  to  insure  success.  First  come  clean 
methods  of  cultivation,  which  implies  that  all  infested  plants 
of  potato  and  weeds  of  the  vicinity  must  be  destroyed,  as 
such  material  affords  a  breeding  place  for  the  insect  and  its 
successful  hibernation.  Sheep  and  hogs  can  be  utilized  in  the 
destruction  of  the  remnants  merely  by  turning  them  into  the 
field.  Crop  rotation  is  desirable,  and  cooperation  is  practically 
a  necessity.  Where  potatoes  are  extensively  grown  in  a  given 
region  their  cultivation  might  be  discontinued  for  a  year.  Other 
plants  than  tomato,  eggplant  and  tobacco  would  answer  as 
alternates,  and  leguminous  crops  are  particularly  indicated, 
owing  to  their  value  as  soil  restorers.  Careful  compact  hill- 
ing is  an  effective  method  in  preventing  infestation,  especially 
to  the  tubers.  Carelessness  in  digging,  which  consists  in  leav- 
ing potatoes  in  the  field  over  night  instead  of  promptly  remov- 
ing them  to  uninfested  shelter,  should  be  avoided. 

The  remedy  that  has  been  used  with  best  results  consists  in 
placing  infested  potatoes  in  tight  receptacles  and  treating  them 
with  bisulphid  of  carbon.  Several  treatments  are  sometimes 
necessary. 

The  Potato-scab  Gnat  {Epidapus  scahici  Hopk.). — Some  forms 
of  potato-scab  are  due  to  the  attacks  of  minute  whitish  maggots 
with  blackheads  which  feed  in  decayed  spots  in  tubers  as 
well  as  upon  healthy  portions.  The  detection  of  these  as  the 
cause  of  scab  is  due  to  the  investigations  of  Dr.  A.  D.  Hopkins,' 

1  Special  Bui.  2,  West  Virginia  Agr.  Exp.   Station,   1895,  pp.  97-111. 


INSECTS    INJURIOUS    TO    POTATO,    ETC. 


22J 


from  whose  publications  the  accompanying  account  has  been 
compiled.  The  most  destructive  of  these  is  known  as  the  potato- 
scab  gnat  which,  in  its  larval  or  maggot  form,  measures  about 
one-sixth  of  an  inch  in  length.  It  is  the  young  of  a  wingless 
female  and  winged  male  gnat  or  midge,  somewhat  like  the 
fickle  midge  treated  in  preceding  pages  as  an  enemy  to  cu- 
cumber. The  female  deposits  eggs  on  tubers  in  the  cellar  from 
autumn  to  spring.  The  maggots  enter  old  scab  spots  or  slightly 
injured  places,  and  under  favorable  conditions  a  generation  is 
developed  every  20  to  25  days.  Later  in  spring  the  gnats 
deposit  their  eggs  in  manure  or  decomposing  material,  on  seed 


145.— Potato  scab-gnat,    o,  Fly;  ;,  larva,  f',  egg;  A,  egg  mass,  etc-    Much 
enlarged.    (After  Hopkins) 


potatoes  and  growing  tubers  in  the  hill,  to  which  they  may  be 
transferred  on  seed  tubers  or  in  decaying  matter.  Once  within 
the  tuber  and  the  conditions  remaining  favorable,  the  potato  is 
destroyed;  but  if  the  maggots  are  driven  out  by  natural  enemies 
or  the  soil  becomes  dry  they  disappear.  The  infested  places 
show  nearly  the  same  characters  as  ordinary  scab,  for  which 
malady  it  may  be  easily  mistaken.  The  conditions  most  favor- 
able to  the  increase  of  this  pest  are  moist,  damp  cellars,  and  wet 
weather  during  the  warmer  season.  They  cannot  thrive  in  dry 
soil  or  in  perfectly  dry  storerooms.  Immense  loss  to  potatoes 
was  caused  in  West  Virginia  during  1891  and  1892,  in  Phila- 
delphia and  probably  in  other  sections  of  the  country.  Under 
favoring  conditions  for  their  increase,  the  gnats  may  be  even 


228  INSECTS    INJURIOUS   TO   VEGETABLES 

more  destructive  than  the  fungus,  on  account  of  their  pene- 
trating while  in  the  larval  stages  deep  into  the  substance  of 
the   tubers,   thus    rendering   them    worthless    for    market. 

Methods  of  Control. — Preventive  measures  that  will  at  the 
same  time  be  effective  against  the  scab  fungus  apply  quite 
as  well  to  the  gnats  and  their  maggots.  Dr.  Hopkins  recom- 
mends the   following  measures    for   protection   against   injury: 

"Select  sandy  or  other  soils  of  a  dry  character  in  which  a 
crop  of  surface  growing  vegetables  or  grain  has  been  grown 
the  previous  year,  and  from  which  the  refuse  has  been  thor- 
oughly removed  in  order  that  the  soil  may  be  as  free  from 
vegetable  matter  as  possible.  Do  not  use  as  fertilizers  animal 
manures,  lime,  ashes,  and  like  substances.  If  a  fertilizer  is 
necessary,  use  only  a  ground  bone,  phosphate,  kainit  and  other 
commercial  fertilizers  of  ?,  like  character.  Select  smooth  and 
healthy  tubers  for  seed.  .  .  .  When  the  potatoes  are  dug, 
and  before  they  are  stored,  carefully  sort  out  all  tubers  showing 
the  least  indication  of  decay,  as  well  as  those  which  are  seri- 
ously affected  with  scab.  Do  not  plant  the  same  land  in  pota- 
toes for  at  least  three  years  after  a  potato  crop  is  taken 
from  it." 

Soak  seed  potatoes  in  a  solution  of  corrosive  sublimate  or 
formalin  according  to  directions  furnished  in  the  chapter  on 
insecticides.  In  case  a  piece  of  land  is  especially  favorable 
for  the  production  of  potatoes  of  excellent  quality,  if  the  pre- 
caution is  taken  to  remove  and  burn  all  rubbish,  such  as  potato 
tops,  weeds,  refuse  tubers,  etc.,  the  same  land  may  be,  by 
judicious   fertilizing,   planted  in  potatoes  every  alternate  year. 


CHAPTER   XIV 

INSECTS  INJURIOUS  TO  THE  TOMATO 

In  the  introduction  to  the  chapter  on  insects  affecting  potato, 
eggplant,  and  similar  crops,  it  was  stated  that  nearly  all  of  these 
insects  affect  to  a  less  extent  the  tomato.  The  species  which 
will  be  here  mentioned  affect  more  particularly  the  tomato, 
and  exceptionally  potato  and  similar  crops.  The  most  im- 
portant are  the  tomato  or  tobacco  worms,  the  common  stalk- 
borer,  often  so  abundant  on  tomato  as  to  be  known  as  the 
tomato  stalk-borer,  which  has  previously  been  treated  (page 
199),  and  the  tomato  fruit  worm,  or  the  corn-ear  worm.  The 
aphides  which  infest  potato,  eggplant,  etc.,  are  likely  to  attack 
tomato  and  there  are  two  additional  species  which  have  been 
observed  on  the  latter.'  Mealy-bugs,  thrips,  plant-bugs  and 
other  sucking  insects  also  feed  on  it. 

The  Tomato  Worms. — The  large  green  "worms"  that  eat 
tomato  leaves  are  well  known.  There  are  two  distinct  species 
of  them,  closely  allied,  much  alike  in  all  their  stages,  and 
practically  indentical  in  habits.  They  are  called  indiscriminately 
tomato  or  tobacco  worms  and  "hornblowers."  In  the  District 
of  Columbia  and  vicinity,  the  two  species  are  of  nearly  equal 
occurrence  as  regards  numbers  on  both  tomato  and  tobacco. 
They  are  the  larvae  of  large  sphinx  moths. 

The  tomato  worm  (Phlegcthontiiis  quinquemaculata  Haw.). — 
The  tomato  or  northern  tobacco  worm  is  nearly  as  thick  as 
one's  little  finger,  and  about  three  and  a  half  inches  long  when 
extended.  The 'horn  is  larger  and  less  curved,  and  usually 
dark  In  color,  whereas  the  Southern  species  has  a  shorter  and 

^Rliopalosiphum  solani  Thos.   and   Ncctarophora   crigeronensis  Thos. 

229 


230 


INSECTS    INJURIOUS    TO   VEGETABLES 


more  curved  red  horn.  On  the  sides  of  the  body  are  eight 
longitudinal  stripes  which  are  met  by  a  similar  number  of 
horizontal  stripes,  each  segment  forming  an  angle  (fig.  146,  b). 
The  moth  (a)  which  produces  this  tomato  worm  has  a  wing 
expanse  of  four  inches  or  less.  It  is  the  paler  form,  and  the 
bright  orange  spots  on  the  sides  of  the  abdomen  are  not  so 


Fig.    146.— Tomato  worm.     a.  Moth:  b,  full-grown  caterpillar;  c,  pupa.      Half  natural 
size.    (After  Howard,  U-  S.  Dept.  Agr.) 


vivid  as  in  the  Southern  species  and  only  four  in  number, 
whereas  the  Southern  form  has  five.  The  hind-wings  are 
marked  with  zigzag  lines  more  pronounced  than  in  the  Southern 
species.  The  dark  mahogany  brown  pupae  of  both  are  fre- 
quently turned  out  of  the  ground  by  the  spade  in  early  spring 
and  later.  They  are  the  possessors  of  a  handle-shaped  process 
projecting  from  the  head,  that  in  the  present  species  (fig.  146.  c) 
being  longer  than  in  the  Southern  (fig.  148,  c),  indicative  of  the 


INSECTS    INJURIOUS   TO    THE   TOMATO  23I 

longer  or  shorter  proboscis  of  the  moth  of  each.     The   pupae 
measure  about  two  inches  in  length. 

The  Northern  species  occurs  throughout  the  United  States 
and  into  Canada.  It  is  also  found  on  Jamestown  weed,  matri- 
mony vine  and  ground  cherry.  The  moths  appear  from  May  to 
June,  according  to  locality  and  season,  and  as  far  north  as 
New  York  City  two  generations  are  annually  produced.  The 
writer  and  others  have  noted  two  generations  in  Maryland  and 
Virginia,  while  as  far  south  as  Florida,  according  to  Quain- 
tance,  a  third  generation  occurs.  The  moths  deposit  their 
eggs,  usually  singly,  on  the  under  surface  of  leaves.  The  eggs, 
according  to  Alwood's  observations  in  Virginia,  hatch  in  from 
four  to  eight  days,  and  the  caterpillars  in  the  course  of  their 
growth  cast  their  skins  four  times  in  less  than  a  month.  When 
full  grown  they  burrow  into  the  soil  and  transform .  to  pupae. 
Both  "worms"  are  sometimes  quite  dark  in  color,  but  when  they 
turn  nearly  black  they  are  usually  infected  by  a  bacterial  dis- 
ease, which  invariably  kills  them  (fig.  147). 


mmm^ 


J  jf 


Fig.  147.— Southern  tobacco  worm  dead  and  shriveled  from  bacterial  disease.      Natural 
size.    (After  Howard,  U.  S.  Dept.  Agr.) 

Few  observing  persons  have  failed  to  see  at  sometime  in 
their  lives  the  caterpillars  of  these  or  other  sphinx  moths  en- 
tirely covered  with  little  white  oval  cocoons.  These  produce 
small  four-winged  parasites,  and  it  is  owing  to  the  abundance 
of  these  and  the  bacterial  disease  that  the  insects  are  not 
more  numerous  than  they  are. 

Remedies. — The  amount  of  damage  done  by  tomato  worms 
will  vary  according  to  the  vigilance  of  the  grower.  On  small 
patches  the  "worms"  are  readily  seen  after  a  little  experience, 


2^2 


INSECTS    INJURIOUS    TO   VEGETABLES 


and  can  be  picked  off  by  hand  and  destroyed,  and  if  this  is 
carefully  done  little  apprehension  may  be  experienced  of  dam- 
age. Clean  culture  and  crop  rotation  are  always  to  be  prac- 
ticed and  the  leaving  of  tobacco  suckers,  or  abandoned  rem- 
nants should  be  avoided,  as  the  "worms"  frequently  remain 
in  the  field  until  the  plants  are  killed  by  frost.  It  should  be 
unnecessary  to  add  that  the  worms  may  be  killed  by  spraying 
Mrith  arsenicals.  Turkeys  are  utilized  in  destroying  these  in- 
sects in  the  South. 

The  Southern  tobacco  worm  (Phlcgcthontins  sexta  Joh.). — 
The  differences  of  this  species  and  the  preceding  have  been 
pointed  out.  In  brief,  the  moth  (fig.  148,  a)  is  darker,  and 
the  five  orange  spots  on  the  body  are  larger  and  brighter.  The 
"worm"  has  only  seven  oblique  white  lines  on  the  sides,  and 


Fig.  148.— Southern  tobacco  worm.    a.  Moth;  b,  full-grown  caterpillar;   c,  pupa-    Half 
natural  size.     (After  Howard,  U.  S-  Dept.  Agr.) 

the  tail  is  more  curved  and  red.  The  pupa  has  a  shorter 
proboscis.  The  Southern  tobacco  worm  is  distributed  through 
the  United  States  from  the  Atlantic  to  the  Pacific,  and  from 


INSECTS    INJURIOUS  TO   THE   TOMATO  233 

Canada  to  the  West  Indies.  No  important  differences  between 
these  two  species  have  been  noted  as  regards  habits,  time  of 
appearance,  susceptibiHty  to  diseases  and  to  parasitic  attack. 
In  the  writer's  experience,  the  two  species  undergo  their  trans- 
formations throughout  in  about  the  same  time. 

Remedies  are  the  same  as  for  the  tomato  worm  proper  previ- 
ously treated. 

The  Tomato  Fruit  Worm  (Hcliothis  obsoleta  Haw.). — This 
insect,  as  most  modern  farmers  are  aware,  is  the  same  species 
as  the  bollworm  or  corn-ear  worm.     It  has  been  treated  from 


Fig.  !49.— Tomato  fruit  worm  boring  in  tomato.     (After  Riley) 

the  Standpoint  of  a  cotton  pest  in  innumerable  publications,  and 
is  considered  among  corn  insects  on  page  207,  but  as  yet  we 
have  discovered  no  direct  remedy  for  it  in  its  occurrence  on 
tomato.  It  is  frequently  the  cause  of  serious  trouble  to  tomato 
growers  over  large  areas,  due  to  the  "worms"  eating  into  and 
destroying  the  green  and  ripening  fruit. 

Remedies. — For  the  protection  of  tomatoes,  it  is  advisable  not 
to  plant  in  proximity  to  corn  or  cotton  fields  or  on  ground 
that  has  been  grown  the  previous  year  to  these  crops  or  to 
beans  or  cowpeas.  all  of  which  are  favorite  host  plants  of  this 
pest;    nor    should    land   be    planted    with    tomatoes    in    infested 


234  INSECTS    INJURIOUS   TO   VEGETABLES 

regions  until  it  has  been  fall  or  winter  plowed.  Although  no 
reports  are  available  of  satisfactory  experiments  having  been 
performed  in  spraying  for  this  species  in  its  occurrence  on  to- 
mato, it  is  possible  that  a  spray  of  Paris  green  and  Bordeaux 
mixture,  or  of  either  alone,  might  be  satisfactory.  It  is  there- 
fore suggested  that  three  out  of  four  plats  of  equal  size  be  treat- 
ed experimentally  in  each  of  the  manners  described,  the  fourth 
plat  to  be  left  untreated,  so  that  the  effects  can  be  noted.  Spray- 
ing may  be  practiced  up  to  about  a  week  from  the  time  of  the 
fruit  ripening  without  danger  of  poisoning  human  beings. 

Miscellaneous  Insects. — Of  insects  most  to  be  feared  when 
the  plants  are  first  set  out  are  cutworms  of  various  species.  The 
tomato  grower  is  well  acquainted  with  these  pests,  and  no 
description  of  their  methods  is  necessary  here,  beyond  the  state- 
ment that  they  cut  off  and  destroy  more  than  they  eat  and  re- 
setting is  frequently  necessary.  Cutworms  are  discussed  more 
fully  on  pages  49  to  56. 

Flea-beetles  also  attack  the  plants  soon  after  they  are  set  out. 
Their  injuries  can  be  prevented  by  dipping  the  young  plants 
before  setting  in  a  solution  of  arsenate  of  lead,  about  i  pound 
to  50  gallons  of  water,  or  Paris  green,  i  pound  to  100  gallons. 
See  page  65  on  flea-beetle  remedies. 


CHAPTER   XV 

INSECTS  INFESTING  THE  SWEET  POTATO 

The  sweet  potato  is  a  staple  from  New  Jersey  and  Maryland 
southward.  It  is  seldom  that  plants  are  not  more  or  less  in- 
fested by  insects,  and  of  these  the  tortoise  beetles  are  con- 
spicuous because  of  the  holes  which  they  eat  in  the  leaves.  As 
the  crop  is  started  under  glass  and  transplanted,  it  is  subject  to 
attack  by  cutworms  and  similar  insects.  There  are  several 
other  defoliators,  blister  beetles,  the  larvae  of  sawflies,  a  hawk- 
moth  and  others;  flea-beetles  sometimes  do  considerable  injury, 
while  in  the  extreme  South  the  sweet-potato  root-borer  is  be- 
coming an  important  pest  from  its  destruction  of  the  tubers. 
In  spite,  however,  of  a  considerable  number  of  insects  which 
attack  this  plant,  it  does  not,  on  the  whole,  suffer  very  material 
injury  save  in  restricted  areas  and  in  years  when  certain  pests 
are  abnormally  abundant.  The  root-borer,  however,  threatens 
to  be  a  permanent  pest  in  the  Gulf  region. 

The  Sweet-potato  Root-borer  {Cylas  formicarius  01.).— In- 
jui^y  by  this  insect  in  North  America  was  first  noticed  about 
1877  near  New  Orleans,  La.,  when  it  was  claimed  to  threaten 
the  destruction  of  the  sweet  potato  crop  of  the  country,  a  pre- 
diction which  was,  happily,  not  verified  until  about  1903. 

The  adult  is  a  weevil  of  ant-like  form  except  for  the  long 
snout  which  it  possesses  (fig.  150,  0) .  It  is  small,  about  one- 
fourth  of  an  inch  in  length,  including  the  snout,  the  elytra  are 
shining  dark  blue,  the  head  and  snout  darker  blue,  and  the 
thorax  and  long  legs  shining  red.  The  larva  (b,  c)  when  grown 
is  about  one-fourth  of  an  inch  long,  white,  with  brown  head  and 
darker  mouth-parts. 

235 


236 


INSECTS    INJURIOUS    TO   VEGETABLES 


This  sweet-potato  borer  is  of  Oriental  origin,  and  its  native 
habitat  is  credited  to  Cochin  China.  It  was  probably  in- 
troduced from  the  West  Indies  into  Louisiana  and  Florida,  and 
from  the  former  States  into  Texas.  The  female  deposits  her 
eggs  in  the  vines  near  the  ground,  and  the  larvae  after  hatch- 
ing tunnel  through  the  tubers,  and  the  vines  die.  Frequently 
tubers  are  so  badly  riddled  and  have  such  a  bitter  taste  that 
neither  fowls  nor  swine  will  eat  them.  The  species  is  capable 
6 


Fig.  150.— Sweet-potato  root-borer,  a.  Male  beetle;  ^  ,  antenna  of  male,  enlarged;  ?, 
antenna  of  female,  enlarged;  b,  pupa;  c,  larva,  dorsal  view;  d,  larva,  side  view.  All 
enlarged.     (After  Howard  except  d,  original.) 

of  undergoing  transformation  from  egg  to  adult  in  about  31 
days  and  hence  as  many  as  four  generations  might  be  produced 
in  a  year.  Considerable  injury  has  been  inflicted  for  a  num- 
ber of  years  in  Louisiana  and  in  Texas. 

Remedies. — Care  should  be  exercised  not  to  transport  tubers 
from  infested  localities  to  uninfested  ones.  If  not  too  badly 
damaged  the  tubers  may  be  disinfected  with  carbon  bisulphid.^ 
small  tubers  should  be  fed  to  hogs,  and  badly  infested  ones 
should  be  burned  with  the  vines. 

The  Sweet-potato  Tortoise  Beetles  (Cassidiiii). — In  many 
sections,  particularly  where  sweet  potato  is  grown  largely 
for  market,  this  crop  is  attacked  by  tortoise  beetles  of  which 

1  See  Farmers'  Bui.  No.  145,  U.   S.   Department  Agriculture. 


INSECTS    INFESTING   THE    SWEET    POTATO 


^17 


half  a  dozen  species  are  common.  They  also  affect  morning- 
glory;  it  is  seldom,  in  fact,  that  the  latter  plants  are  free  from 
their  attacks.  The  most  common  form  of  injury  is  manifested 
by  numerous  more  or  less  rounded  holes  eaten  in  the  leaves, 
and  this,  if  traced  to  its  source,  will  usually  be  found  to  be  due 
to  the  presence  of  the  tortoise  beetles.  Some  of  these  insects 
are  truly  wonderful.  The  golden  tortoise  beetle,  known  as 
"the  gold  bug,"  is  one  of  the  most  beautiful  creatures  imaginable 
when  it  is  resting  at  ease  or  feeding  in  daylight.  At  this  time 
it  has  the  appearance  of  a  globule  of  burnished  gold.  If  the 
beetle  is  disturbed  this  golden  color  disappears,  and  it  fades 
also  toward  sundown  and  does  not  remain  after  death  in  dried 
specimens.  The  larvae  which  produce  these  beetles  are  also 
remarkable    because    of   their   singular    habits.      They    are    the 


Fig.  151.— Golden   tortoise  beetle.      o,   Larvae  working  on  leaf;     h<  larva  divested  of 
"  pack  ";  c,  pupa;  rf,  beetle,    a,  Natural  size;  b,  c,  d,  enlarged.     (After  Riley) 

possessors  of  peculiar  forked  appendages  which  serve  as  recep- 
tacles for  their  cast-off  skins  and  for  their  excrement  as  it  is 
voided.  When  divested  of  the  cast  larval  skins  and  excrement, 
the  larvae  are  seen  to  be  fiat  below,  like  the  beetles,  and  convex 
above,  the  margins  projecting  into  peculiar-shaped  spines. 
These  larvae  are  sometimes  termed  "pedlars,"  the  fork  with  its 
load  being  designated  as  the  pack.  Beetles,  as  well  as  larvae, 
feed  chiefly  on  the  under  surfaces  when  not  exposed  to  direct 
sunlight.  Injury  is  mainly  to  young  plants,  the  beetles  making 
their  first  appearance  at  about  the  time  plants  are  reset.  Soon 
after  appearing  the   females  begin   laying  eggs,   and   in   about 


238 


INSECTS    INJURIOUS   TO    i^EGETABLES 


live. 


a  week  or  a  few  days  longer  the  larvse  hatch  and  assist  the 
beetles  in  their  work  of  destruction.  Indications  are  that  all  of 
these  tortoise  beetles  are  single-brooded,  hibernation  taking 
place  in  the  adult  stage. 

The  Golden  Tortoise  Beetle  (Coptocycla  hicolor  Fab.)  is  the 

most  striking  of  the  tortoise  beetles,  and  well  known  and  destruc- 

In  this  form    (fig.   151)    the  entire  body  is  golden  with 

exception  of  the  borders;  that  is,  when  the  insect 

is  resting  on  leaves  exposed  to  the  sun.     If  a 

specimen  be  captured  the  colors  fade  to  a  dull, 

deep  orange,  sometimes  with  a  few  golden  spots 

remaining,  and  two  black  spots  are  noticed  near 

the  middle  of  the  insect.     The  size  varies  from 

two-twelfths  to  three-twelfths  of  an  inch.     The 

larva    {b)    carries    its    "pack"   directly   over   the 

egg.    Much  en-   back,  and  the  excrement  is  arranged  in  a  more 

larged.      (After  ,  ,  ,  ,    ,      , 

Riley.)  ^r  less  regular  three-lobed  pattern. 

The  Mottled  Tortoise  Beetle  (Coptocycla  guttata 
01.). — This  species  is  about  equally  as  common  and  of  the  same 
size  as  the  golden  tortoise  beetle.  It  is  shown  in  its  various 
stages  in  figure  153.   It  differs  in  having  the  elytral  ground  color 


Fig.  152.-Golden 
tortoise      beetle 


Fig.  153.— Mottled  tortoif^e  beetle,    a,  larva;  b,  pupa;  c,  beetle.    (After  Riley) 


black, 'extending  at  the  shoulders  on  each  side.  Sometimes  it  is 
flecked  with  gold  and  at  other  times  with  yellow.  The  larva 
(a)  is  green,  with  a  bluish  shade  down  the  back.  It  carries 
its  excrement  and  cast  skins  in  irregular  broad  masses,   fre- 


INSECTS    INFESTING   THE   SWEET    POTATO 


i239 


quently  branching  as  in  some  other  species.  Before  changing  to 
pupa  it  removes  the  faeces  from  its  fork.  The  pupa  (b)  is  also 
green,  with  a  black  ring  around  the  base  of  the  first  abdominal 
pair  of  spiracles. 

The  Two-striped  Sweet-potato  Beetle  (Cassida  bivittata  Say.). 
— In  1869  this  was  stated  to  be  the  most  common  of  the  tortoise 
beetles  occurring  on  sweet  potato  seeming  to  be  confined  to  that 


Fig.    154.— Two-striped  sweet-potato  beetle.     1,  Larvas  at  work  on  leaves;  2,  larva; 
3  pupa;  4.  beetle.     J.  Natural  size;  2,  J,  4,  enlarged.   (From  Riley) 

plant.  From  the  District  of  Columbia  northward,  where  the 
writer  has  observed  it,  it  is  much  less  abundant  than  the  two 
preceding,  hence  it  is  of  less  importance  economically.  The 
beetle  (fig.  154,  4)  is  yellow  and  has  two  black  stripes  on  the 
elytra,  whence  the  common  name.  The  larva  (2)  is  dirty 
whitish  or  yellowish,  showing  a  rather  indistinct  line  along  the 
back.  From  similar  larvse  on  sweet  potato  it  can  be  known  from 
the  fact  that  it  does  not  use  its  fork  for 
carrying  excrement,  but  only  as  a  repository 
for  cast  skins.  This  fork  is  usually  elevated  at 
an  angle  of  about  45°,  which  suggests  the  idea  of 
a  handle. 

The  Black-legged  Tortoise  Beetle  (Cassida 
ni gripes  01.). — From  other  sweet-potato  tortoise 
beetles  this  species  (figs.  155,  156)  may  be  dis- 
tinguished by  its  larger  size.  It  measures  nearly 
one-third  of  an  inch.  Like  the  golden  tortoise 
beetle,  it  is  reddish  except  when  in  bright  sunshine,  and  has  the 
same  power  of  assuming  a  golden  hue,  apparently  at  will.     Its 


Fig.  15  5. -Black- 
legged  tortoise 
beetle.  (After 
Riley.) 


240 


INSECTS    INJURIOUS    TO    VEGETABLES 


distribution  extends  from  ocean  to  ocean,  and  it  is  apparently 
more  abundant  on  the  Pacific  coast  than  eastward. 

Remedies. — The    tortoise    beetles    which    prey    upon    sweet 


Fig.    156.— Black-legged  tortoise  beetle,     a,  Larvse,   natural  size;  f>,  larva  divested  of 
pack    of  excrement;  c,  pupa.    Both  enlarged.    (After  Riley) 

potato  are  not  as  a  rule  of  great  economic  importance.  The 
remedies  prescribed  below  for  the  sweet-potato  flea-beetle  are 
about  all  that  are   usually   required. 

The  Sweet-potato  Flea-beetle  {Chcctocncma  conftnis  Lee). — 
In  parts  of  the  United  States,  notably  in  New  Jersey  and  Mary- 
land, this  insect  causes  considerable  injury  to  the  sweet  potato 
by  eating  out  channels  along  the  veins  on  both  surfaces  of  the 
leaves  soon  after  the  plants  are  set  out.  This  gives  the  leaves 
the  appearance  of  having  been  attacked  by  a  leaf-miner.  Soon 
after  attack  on  young  plants,  the  entire  surface  becomes  seared. 
When  the  insect  occurs  in  numbers  leaves  are  destroyed  and 
plants  are  killed  outright.  Attack  is  most  severe  on  ground 
previously  grown  in  sweet  potato,  and  also  follows  the  clear- 
ing of  fields  which  have  been  allowed  to  grow  in  bindweed,  one 
of  the  insect's  natural  food  plants. 

Remedy. — Plants  before  setting  out  should  be  dipped  in  a 
strong  solution  of  arsenate  of  lead,  and  one  or  two  sprayings 
of  the  leaves  with  arsenicals  a  week  or  two  later  is  about  all 
that  is  needed,  because  the  plants,  being  hardy,  easily  recuperate 
from  attack  and  suffer  little  injury  other  than  that  of  defolia- 


INSECTS    INFESTING   THE   SWEET    POTATO  24I 

tion.  The  first  application  is  to  accomplish  the  destruction  of 
the  beetles  before  they  deposit  their  eggs,  and  the  second  and 
third  are  to  kill  beetles  that  may  come  from  other  plants.  Rota- 
tion of  crops  and  the  avoidance  of  planting  in  the  vicinity  of 
neglected  ground  that  has  grown  up  with  bindweed  and  wild 
morning-glory  are  also  advisable. 

The  Common  Sweet-potato  Sawfly  (Schi::occi'us  cbenus  Nort.). 
— The  larvx  of  two  species  of  sawflies  have  been  observed  doing 
injury  to  sweet  potato. 
They  are  comparatively 
new  as  pests  and  of  similar 
habits  and  distribution  from 
New  York  to  the  Gulf  and 
northward  to  Nebraska. 

The  present  is  like  other 
sawflies,  four-winged,  and 
somewhat  smaller  than  a 
house  fly,  the  body  is  black, 
and    the    wings    infuscated 

_      1      1  r^,  ,        ,  Fig.    \Z7 .—Eubadizon   schiaoceri.     Parasite  of 

or    dusky.        The     male     has        %^eet-potato  sawfly.    (After  insect  Life) 

.  forked    antennae    while    the 

female  has  shorter  simple  ones.  Eggs  are  deposited  in  the  leaf  of 
sweet  potato.  Attack  has  been  observed  in  August  and  Sep- 
tember in  Mississippi,  and  a  parasite  (fig.  157)  has  been  reared 
from  the  larva.  This  parasite,  and  a  tachina  fly,  which  also 
preys  on  it,  no  doubt  hold  the  insect  in  check  and  prevent 
serious  injury. 

The  Larger  Sweet-potato  Sawfly  {Schizoccrus  privatus 
Nort.). — The  first  record  that  we  have  of  injury  by  the  larvae 
of  this  sawfly  was  in  July,  1890,  when  it  damaged  sweet  potato 
in  Virginia.  At  that  time  plants  that  were  attacked  produced 
no  yield  whatever.  This  sawfly  is  larger  than  the  preceding, 
the  wing  expanse  being  nearly  3/5  of  an  inch,  and  both  sexes 
have  yellow  abdomens.     Other  differences  can  be  made  out  by 


242 


INSECTS    INJURIOUS    TO    VEGETABLES 


comparison  of  the  illustration  of  each.  According  to  Marlatt, 
deposition  of  the  eggs  is  on  the  under  surface  of  the  leaf,  and 
by  reference  to  figure  158,  a,  it  will  be  seen  that  eggs  are 
placed  usually  in  parallel  rows  bordering  the  larger  veins  of 


Fig.  158. — Larger  sweet-potato  sawfly.  a,  Female  sawfly  S  antenna  of  male;  b  young 
larva;  c,  section  of  infested  sweet-potato  leaf,  showing  egg  deposit'  d  same  showing  larva 
hatching  and  feeding,     a,  b,  d,  S  ,  Enlarged;  c,  natural  size.    (Adapted  from  Marlatt.) 


the  leaf.  Larvas  are  seen  hatching  from  the  pouch-like  egg 
receptacles  or  blisters  at  b. 

Remedies. — Both  these  sawfly  larvae  when  abundant  may  be 
easily  controlled  by  the  prompt  application  of  hellebore  or 
arsenicals  when  they  make  their  first  appearance. 

Cutworms. — Since  sweet  potato  is  cultivated  in  seed-beds, 
it  is  subject  to  the  ravages  of  cutworms  when  set  out  in  newly- 
plowed  fields.  One  of  these,  the  dark-sided  cutworm  (Car- 
neades  messoria  Harr.),  appears  to  be  particularly  identified 
with  attack  of  this  nature.  It  is  a  common  species,  and  in  addi- 
tion to   various   garden   crops   seems   to   revel   in   onions.     A 


INSECTS    INFESTING    THE    SWEET    POTATO  243 

more  complete  account,  with  illustrations,  has  been  furnished 
on  page  246.  The  variegated  cutworm,  in  years  when  it  in- 
dulges in  uprisings,  also  injures  sweet  potato  and  some  other 
cutworms  and  other  caterpillars  of  less  importance  occasionally 
cause  losses  to  this  plant. 

Remedies  for  these  insects  are  duly  treated  on  page  54. 

Mealy-bugs  {Dactylopius  spp.). — A  species  of  unidentified 
mealy-bug  has  been  mentioned  by  Dr.  J.  B.  Smith  as  destructive 
in  Salem  County,  N.  J.,  in  1901,  to  sweet-potato  in  forcing  beds.' 
They  were  found  clustered  at  the  bases  of  the  sprouts  and  of 
the  small  leaves.  It  is  not  probable  that  these  insects  would 
survive  normal  outdoor  conditions  when  plants  are  set  out  in 
spring  in  New  Jersey,  but  in  the  Gulf  region  they  doubtless 
would  develop  out-of-doors  quite  as  well  as  under  glass.  For 
protection  against  mealy-bugs  cellars  and  storerooms  should  be 
thoroughly  whitewashed  and  cleaned  before  the  seed  tubers  are 
stored  and  the  temperature  should  be  kept  low  while  in  the  beds 
where  the  roots  are  forced  in  spring.  Cleanliness  should  be 
observed  and  the  roots  should  be  inspected  before  putting  them 
in,  and  such  as  show  the  mealy-bugs  should  be  rejected  and 
destroyed. 


Rent 


.  Dept.  Ent.  N.  J.  Agr.  CoU.  Exper.  Sta.  for  1901    (1902),  n.  489. 


CHAPTER    XVI 

INSECTS   INJURIOUS   TO   MISCELLANEOUS 
VEGETABLE  CROPS 

THE  ONION  AND  OTHER  BULB  CROPS 

Bulb  crops  are  so  similar  that  what  will  attack  one  is  apt  to 
feed  on  the  others.  Six  crop  plants  (genus  Allium)  are  in- 
cluded in  this  group:  the  common  onion,  Welsh  onion,  shallot, 
cive,  leek  and  garlic.  Of  these  onty  the  first  is  grown  to  any 
extent  in  North  America.  "The  onion,"  some  one  has  remarked, 
"is  one  of  those  strenuous  vegetables  about  which  one  can- 
not be  indifferent.  One  either  yearns  for  it  with  a  passionate 
longing  or  else  utterly  repudiates  it."  The  same  is  true  as  re- 
gards insects,  since  few  species  are  overfond  of  it.  The  leading 
species  are  the  onion  maggot  and  onion  thrips.  A  few  insects 
of  omnivorous  tendencies,  however,  not  infrequently  do  much 
injury  to  this  plant.  Of  such  are  some  forms  of  cutworms,  and 
especially  the  dark-sided  cutworm,  wireworm,  and  the  imbri- 
cated snout-beetle.  The  pungent  odor  of  the  onion  and  its 
kind  rende-rs  it  unpalatable  to  many  insects,  but  some  resort  to 
these  plants  in  the  absence  of  other  vegetation. 

Insect  injury  to  onion  and  related  plants  is  peculiarly  local 
or  intermittent,  and  in  spite  of  the  injurious  species  which 
will  be  treated,  and  the  immense  amount  of  damage  that  they 
have  done,  it  is  no  uncommon  sight,  but  in  fact  the  rule,  to 
see  fields  grown  to  these  crops  year  after  year  for  long  periods 
without  their  sustaining  any  material  harm.  Such  is  the  case 
about  the  District  of  Columbia,  where  no  insects  what- 
244 


INSECTS    INJURIOUS   TO  MISCELLANEOUS   CROPS  245 

ever  have  been  noticed  in  recent  years  injuriously  affecting  the 
onion  crop. 

The  Imported  Onion  Maggot  (Pegomya  cepetorum  Meade). — 
This  maggot  injures  the  onion  by  eating  into  the  bulbs,  the 
subsequent  decay  of  the  affected  portions  frequently  destroying 
them.  It  is  a  most  important  drawback  to  the  culture  of  onions 
here  and  in  Europe,  from  which  continent  it  was  introduced 
years  ago.  It  is  nearly  related  to  the  seed-corn,  and  cabbage, 
maggots  treated  in  former  pages.  In  the  adult  state  it  re- 
sembles, as  do  the  others,  the  common  house  fly.  The  average 
size  is  a  little  larger  than  the  flies  of  the  two  root-maggots  that 
have  been  mentioned,  the  body  being  about  3/16-inch  long  and 
the  wing  expanse  nearly  3/8-inch.  The  maggot  itself  and  the 
puparium  can  be  distinguished  from  those  of  other  root-mag- 
gots only  by  careful  comparison. 

The  life  history  is  very  like  that  of  the  cabbage  maggot, 
the  differences  being  due  to  the  different  character  of  the 
vegetables  attacked.  It  follows  that  the  natural  enemies  which 
prey  on  one  are  liable  to  attack  the  others,  and  the  remedial 
measures  to  be  adopted  are  also  much  the  same. 

Remedies. — For  a  discussion  of  remedies  the  reader  is  re- 
ferred to  the  account  of  the  seed-corn  maggot. 

The  Black  Onion  Fly  (Tritoxa  flcxa  Wied.).— This  is  an 
old  enemy  of  onion  and  a  native 
species,  recorded  from  the  Atlantic 
coast  to  Illinois.  The  fly  is  about 
one-third  of  an  inch  long,  black, 
with  three  oblique  white  stripes 
on  each  wing.  The  maggot  itself 
is  white  and  larger  than  the  root- 
feeding  species  previously  treated.  Fie-  159.-Black  onion  fly.  Three 
T^   ,       ,  .  ,     .         ,      ,    .       •  times  natural  size.    (After  Walsh) 

It  feeds  on  onions  and  cives  both  m  ' 

the  field  and  in  store.    General  remedies  are  the  same  as  for  the 


246 


INSECTS    INJURIOUS   TO   VEGETABLES 


seed-corn  maggot    (page   108).     In  addition  bisulphid  of  car- 
bon is  desirable  for  the  treatment  of  stored  onions. 

Cutworms  (Euxoa  messoria,  etc.) — Onions,  as  has  been 
stated,  are  not  particularly  favored  by  many  insects  of  om- 
nivorous tendencies,  but  the  variegated  cutw^orm  is  quite  de- 
structive to  it  and  there  is  one 
other  species,  the  dark-sided 
cutworm,  which  might  well 
be  called  the  onion  cutworm, 
from  the  great  injuries 
which  it  causes  to  this  crop. 
In  1885,  near  Goshen,  New 
York,  this  cutworm  (shown 
in  figure  160)  threatened  the 
extinction  of  the  onion  in- 
dustry, the  annual  value  of 
which  was  estimated  at  half 
a  million  dollars.     Although 

Fig.    160. -Dark-Sided  cutworm  (£.xo^m..-    ^^^  j^    worked    day    and 

soyia).  fl,  Cutworm;  6,  moth.  (After  Riley)         . 

night  to  keep  down  the  pest, 
the  yield  was  reduced  during  that  and  the  following  year  about 
one-half,  or  a  total  cash  loss  of  about  $500,000. 

Remedies. — This  species  can  be  treated  in  the  usual  manner 
for  cutworms. 

The  Onion  Thrips. — For  an  account  of  the  onion  thrips  see 
page  89. 

RHUBARB 

Rhubarb  or  pie-plant  is  rather  unusually  exempt  from  in- 
jurious attack  by  insects,  a  fact  which  is  largely  to  be  accounted 
for  by  the  rapid  and  early  growth  of  this  plant,  its  vigor,  and 
large  stalks  and  leaves.  No  natural  enemies  appear  to  have 
been  introduced  with  it,  and  it  generally  attains  full  market 
growth   before   the   appearance   of   most   insects   which   might 


INSECTS    INJURIOUS  TO    MISCELLANEOUS    CROPS         247 


injure  it.  Several  species  attack  rhubarb,  but  only  two  or 
three  appear  to  prefer  it  to  other  plants  cultivated  in  this 
country.  Two  insects  that  are  specially  identified  with  rhubarb 
are  the  rhubarb  curculio  and  the  rhubarb  flea-beetle.  It  is  also 
quite  subject  to  the  attack  of  aphides. 

The  other  insects  which  infest  this  plant  are  general  feeders, 
such  as  cutworms  and  some  other  caterpillars  and  a  few  leaf- 
feeding  beetles. 

The  Rhubarb  Curculio  (Lixiis  concavns  Say.). — Injury  by 
the  above-mentioned  species  is  accomplished  by  the  beetles  punc- 
turing the  stalks  for  food,  although 
occasionally  they  attack  the  leaves 
and  seed  stalks.  This  causes  the 
plant  to  exude  juice  copiously 
which,  drying,  forms  clear,  tear- 
like drops  (fig.  161).  Eggs  are 
often  deposited  in  the  stems,  but  the 
leaves  do  not  develop,  doubtless 
owing  to  the  moisture  caused  by  the 
beetles'  punctures.  The  larvae  breed 
exclusively  in  weeds,  such  ^as  dock 
(Rumex),  and  occasionally  in  sun- 
flower (Helianthus). 

The  insect  under  discussion  is  a 
large,  rusty-coated  curculio  or 
snout-beetle,  measuring  from  the 
tip  of  its  long  proboscis  about  three- 
fourths  of  an  inch,  and  being  of  the 
form  shown  in  figure  162,  a. 

Remedies. — The  use  of  poisons 
on  rhubarb  during  its  growing 
season  is  out  of  the  question,  but  the  beetles  are  so  conspicu- 
ous that  they  can  readily  be  seen  on  the  leaves,  and  as  they  are 
sluggish  there  is  no  difficulty  in  capturing  them.     They  should 


Fig.  161.— Section  of  rhubarb  stalk 
showing  injury  by  rhubarb  curculio. 
(Author,  U.  S.  Dept.  Agr.) 


248 


INSECTS    INJURIOUS    TO   VEGETABLES 


be  gathered  also  upon  nearby  plants  of  dock,  and  after  the 
eggs  have  been  deposited  on  the  dock  stems  these  plants  should 
be  pulled  up  and  burned  before  the  development  of  the  adults. 
The  Rhubarb  Flea-beetle  (Psylliodes  punctulata  Mels.). — 
This  species  shows  a  great  preference  for  rhubarb  where  ob- 
tainable over  other  vegetables,  among  which  are  cucumber, 
radish,  and  beet.  It  is  dark,  brassy  green,  and  finely  punctulated, 
with  its  femora,  tarsi,   and  the  basal  joints  of  antennre  pale. 


Fig.  162.— Rhubarb  curculio-  a.  Beetle:  i,  egg;  c,  newly-hatched  larva:  la^,  full-grown 
larva:  e.  pupa:  /,  dorsal  view  of  last  abdominal  segments  of  pupa.  All  about  twice 
natural  size.    (Author's  illustration,  U.  S.  Dept.  Agr.) 


obscure  yellowish.  Both  the  upper  and  lower  surface  of  leaves 
are  affected  by  the  beetle  gnawing  through  and  devouring  the 
pulp,  leaving  the  skin  on  the  opposite  side  entire,  which  be- 
comes discolored,  forming  yellowish  brown  freckles  as  the 
leaf  grows  and  expands,  the  skin  at  these  points  becoming  in 
time  torn  and  showing  holes.  '  When  the  beetles  occur  in  num- 
bers leaves  are  sometimes  riddled  by  these  punctures. 

Remedies. — Ordinary  flea-beetle  remedies  are  recommended. 
(See  page  65.) 


INSECTS    INJURIOUS  TO    MISCELLANEOUS    CROPS         249 

LETTUCE 

Of  minor  truck  plants,  which  will  be  considered  in  this  chap- 
ter, lettuce  appears,  on  account  of  its  tender  leaves  and  lack  of 
decided  flavor,  the  most  favored  by  insects.  It  does  not  seem 
to  have  any  insects  specially  attached  to  it,  but  there  is  one 
species,  the  lettuce  earth-louse,  which  may  fall  in  this  category. 
At  least  a  score  of  species  are  known  to  affect  it  occasionally. 
Among  the  most  troublesome  of  these  are  the  common  cabbage 
looper  and  celery  worm,  treated  in  the  consideration  of  insects 
which  affect  cabbage  and  celery  respectively.  Cutworms  are 
not  partial  to  lettuce,  but  some  species,  particularly  the  va- 
riegated cutworm,  attack  it;  a  species  of  thousand-legged  worm 
has  been  recorded  as  being  very  destructive  by  attacking  the 
outside  leaves  near  the  main  stalk  and  four  species  of  aphides 
or  plant-lice  are  recorded  as  feeding  on  lettuce. 

The  Lettuce  Earth-louse  (RJiicobius  lactucce  Fitch).— This 
common  eastern  species  occurs  sometimes  in  destructive  num- 
bers at  the  roots  of  lettuce.  It  is  oval,  dull  whitish,  with  dusky 
legs  and  antennae,  and  measures  less  than  one-tenth  of  an  inch. 
The  entire  body  is  coated  as  though  dusted  with  a  whitish 
powder.  It  should  be  treated  in  the  same  manner  as  the  root- 
aphides  to  which  group  it  belongs. 

OKRA  OR  GUMBO 

The  insect  enemies  of  okra  are  practically  the  same  as  of 
cotton,  which  belongs  to  the  same  botanical  family.  Okra, 
however,  is  little  damaged,  and  the  writer  has  for  several  years 
seen  plantings  that  were  not  seemingly  at  all  injured  by  the 
few  insects  which  were  present.  One  of  the  principal  enemies 
of  okra  is  the  melon  aphis,  which  sometimes  occurs  upon  it  in 
great  numbers.  The  bollworm  enters  the  pods,  but  evinces  no 
special  fondness  for  them.  Several  leafhoppers  are  found  on 
okra,  and  of  these  is  the  waved  sharpshooter    (Oucometopia 


250         INSECTS  INJURIOUS  TO  VEGETABLES 

[Proconia]  iindata  Fab.).  The  foliage  at  times  shows  holes 
where  such  general  feeders  as  the  twelve-spotted  cucumber 
beetle  have  attacked  it,  apparently  in  wantonness,  while  the 
plants  were  still  young. 

SALSIFY 

The  insect  enemies  of  salsify,  or  vegetable  oyster,  were  un- 
der observation  by  Mr.  F.  M.  Webster  some  years  ago.^  He 
records  the  occurrence  of  two  common  species  of  leaf-rollers 
and  three  aphides  on  the  plant,  the  yellow  bear,  or  caterpillar 
of  the  ermine  moth,  and  the  tarnished  plant-bug.  There  are 
other  species  which  attack  it,  all  general  feeders,  but  there  ap- 
pear to  be  few,  if  any,  records  of  injurious  occurrences. 

PEPPER 

Peppers  were  grown  in  the  United  States  until  1904  without 
serious    attack   by    insects    being    re- 
corded.   That  year  a  little  pest  known 
as   the    pepper   weevil    (Anthonomus 
eugenii     Cano)     attracted      attention 
by  its  injuries  to  peppers  of  all  vari- 
eties at  Boerne,  Texas.     This  species 
(fig.  163)  is  a  relative  of  the  notorious 
Mexican   cotton-boll   weevil   and   has 
the  same  origin  and  a  similar  life  his- 
Fig.  163.  — Pepper  weevil.       tory.     It  is  a  native  of  Mexico  from 
St  hS^K's.  Dept       Which  country  it  has  been  introduced 
Agr-)  into  Texas. 

Remedies. — Gathering  and  destroying  the  fallen  pepper  pods 
in  which  the  larva  feeds  and  the  beetle  develops  or  burying 
the  infested  pods  by  bedding  high  and  lowering  the  soil  are 
suggested  as  methods  of  control.  Where  pepper  is  grown  in 
irrigated  land  this  practice  serves  to  check  the  insects,  as  the 

iSee  list,  Insect  Life,  Vol.  II.,  page  259. 


INSECTS    INJURIOUS  TO    MISCELLANEOUS    CROPS         25 1 

decay  of  the  pods  is  hastened  and  the  larvae  are  thus  deprived 
of  a   food  supply/ 

Some  of  the  potato  and  tomato  pests  considered  in  earlier 
pages  occasionally  infest  peppers,  but  do  not  as  a  rule  do  notice- 
able injury.  Among  these  are  the  tomato  worms,  boll  worm, 
white  fly,  and  Colorado  potato  beetle. 

1  This  species  is  treated  under  the  name  of  Anihonomus  aneotvictus  Champ. 
in  Bui.  54,  Bur.  Ent.,  U.  S.  Dept.  Agr.,  pp.  43-48,  and  Bui.  63,  pp.  55-58, 
by  C.   M.   Walker  and   F.   C.   Pratt  respectively. 


CHAPTER  XVII 


BIBLIOGRAPHY 

A  short  list  of  some  of  the  more  important  and  readily- 
available  publications  on  economic  entomology  in  which  the 
insects  injurious  to  vegetable  crops  are  treated  follows.  In 
compiling  such  a  list  some  precedence  is  given  to  the  publica- 
tions of  the  Federal  Department  of  Agriculture  because  as  a  rule 
they  have  a  wider  scope  than  State  Agricultural  Experiment 
Station  publications,  are  printed  in  larger  editions  and  are  ac- 
cessible to  all,  being  for  the  most  part  free  on  application.  Many 
of  these  contain  bibliographical  references.  The  list  begins  with 
works  on  general  and  economic  entomology. 

WORKS  ON  GENERAL  AND  ECONOMIC  ENTOMOLOGY 

1841.  Harris,  T.    W. — Insects   Injurious   to   Vegetation.     Flint  ed., 

1851.     Orange  Judd  Co.,  New  York.     First  ed.,  Cambridge, 

1841. 
1855.  FiTCii,  Asa — Reports  of  the  State  Entomologist  of  New  York. 

I.-XIV.,   Albany.    1855-1870.      (See   Lintner's   First  Annual 

Report,  State  Ent.  New  York,  pp.  294-297.) 
1865.  The   Practical  Entomologist.     Vols.    I.   and   II.     Published 

by  the  Entomological  Society  of  Philadelphia,  1865-1867. 
1868.  The  American  Entomologist,  edited  by  B.    D.   Walsh   and 

C.  V.  Riley.     Vols.  I.-III.,  1868-1880. 
i86g.  Riley,  C.  V. — Reports  of  the  State  Entomologist  of  Missouri. 

I.-IX.     Jefferson  City,  1869-1877. 
1879.  Reports    of    the    Entomologists    of   the    U.    S.    Department   of 

Agriculture.     J.    H.    Comstock    (1879-1880)  ;    C.   V.    Riley 

(1878-1879,  1880-1894).     L.  O.  Howard  (1894  to  date). 
1882.  Lintner,   J.   A. — Reports   of   the   State   Entomologist   of   New 

York,  I.-XIV.     Albany,   i882-'97. 

1882.  Treat,    Mary — -Injurious    Insects    of   the    Farm   and    Garden. 

Orange   Judd    Co.,    1882.      (A    small    work   compiled    from 
Riley's  reports.) 

1883.  Forbes,  S.  A. — Reports  of  the  State  Entomologist  of  Illinois, 

I.-XXIII.     1883-1905- 

1891.  Weed,  C.  M. — Insects  and  Insecticides.    281  pp.,  143  figs.   Han- 
over, N.  H.,  1891. 

1895.  Comstock,  J.  H.  and  Anna  B. — A  Manual  for  the  Study  of 
Insects.    701  pp.,  797  figs.     Ithaca,  N.  Y. 
252 


BIBLIOGRAPHY  253 

1896.  Smith,  J.  B. — Economic  Entomology.    481  pp.,  483  figs.     Phil- 
adelphia, i8g6. 
1902.  Johnson,   W.    G. — Fumigation    Methods.     Orange   Judd    Co., 

New  York.    313  pp.,  83  figs. 
1902.  Sanderson,  E.   D. — Insects   Injurious  to  Staple  Crops.     New 
York.    29s  pp.,  162  figs. 

Bulletins  of  the  Division  and  Bureau  of  Entomology  of  the  U. 
S.  Department  of  Agriculture,  I-XXXIIL,  o.  s.,  1883-1895,  1-71, 
n.  s.,  1896-1907.  (Buls.  19,  23,  29,  S3  and  43  treat  of  insects  injurious 
to  vegetables.)     Insect  Life,  vols.  I.-VII.,  1888-1897. 

Circulars,  Division  and  Bureau  Ent.  U.  S.  Dept.  Agr.,  1891-1907. 
(Circ's.  10,  16,  31,  38,  39,  43,  57,  59,  60,  62,  63,  65,  80  and  87  treat 
of  insects  which  affect  vegetable  crops.) 

The  publications  of  the  various  state  agricultural  experiment 
stations  may  be  obtained  by  residents  of  the  States  where  these 
documents  are  issued. 


GENERAL  CROP  PESTS 

Cutworms.     Smith — Bui.  109,  New  Jersey  Agr.  Exp.  Sta.,  pp.  3-13, 

figs.   1-3,  1895;  Slingerland — Bui.  104,  Cornell  Univ.  Agr. 

Exp.  Sta.,  pp.  553-600,  figs.,  1895. 
Spotted    Cutworm    (Noctua    c-nigrum    Linn).      Chittenden — Bui. 

27,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  54-58,  1901. 
Variegated  Cutworm    {Pcridroiim  saucia   Hbn.    [Agrotis  saiicia]). 

Chittenden — Bui.   29,   n.    s.,   Div.    Ent.    U.    S.    Dept.   Agr., 

pp.  46-64,  1901   (includes  bibliography). 
Black  Cutworm  {Agrotis  ypsllon  Rott.).     Riley— Rept.  U.  S.  Dept. 

Agr.  f.  1884,  pp.  294,  295,  1885. 
Army  Worm   (ricliopliila  unipuitcta   Haw.   [Lcucauia  unipuncta]). 

Howard — Circ.  4,  Div.  Ent.  U.  S.  Dept.  Agr.,  1894;  Slin- 
gerland— Bui.   133,  Cornell  Univ.  Agr.  Exp.  Sta.,  pp.  233- 

258,  1897. 
Fall  Army  Worm  or  Grass  Worm    {Laphygina  frugiperda  S.  & 

A.).    Chittenden — Bui.  29.  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr., 

pp.   13-45,  1901    (Bibliography). 
Wireworms.     Comstock  and  Slingerland — Bui.  33,  Cornell  Univ. 

Agr.  Exp.  Sta.,  pp.  193-272,  figs.,  1891 ;  Slingerland — Bui.- 

107,  Cornell  Univ.  Agr.  Exp.  Sta.,  pp.  37-56,  1896;  Forbes — 

i8th  Rept.  St.  Ent.  Ills.,  pp.  27-51,  1894. 
White  Grubs.     Forbes,  S.  A.— i8th  Rept.  St.  Ent.  Ills.,  pp.  109-145, 

1894;  Bui.  44,  Univ.  Ills.  Agr.  Exp.  Sta.,  pp.  257-281,  1896; 

Chittenden — Bui.  19,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp. 

67-80,  1899. 
Grasshoppers  or  Locusts.     Riley — Bui.  25,  o.  s.,  Div.  Ent.  U.  S. 

Dept.  Agr.,  pp.   1-62,  figs,  and  pis.,   1891.      (Compiled  from 

1st  and  2nd  Repts.  U.  S.  Ent.  Comm.,  etc.) 
Pale-striped  Flea-beetle   (Systcna  blanda  Mels.   [S.  tceniata  Say]). 

Chittenden — Bui.  23,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  23-30, 

1900. 


254  INSECTS    INJURIOUS    TO   VEGETABLES 

Red  Spider  (Tetranychus  bimaculatus  Haw.  [T.  telarius  Authors]). 
Chittenden — Bui.  27,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp. 
35-42,  1 90 1. 

ASPARAGUS 

General.     Chittenden — Bui.  10,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr., 

pp.  54-62,  1898. 
Common  Asparagus  Beetle  (Crioceris  asparagi  L.).  Chittenden — 

Ybk.  U.  S.  Dept.  Agr.  f.  1896  (1897),  pp.  341-349;  Bui.  66, 

Bu.  Ent.,  pp.  6-9,  1907 
Twelve-spotted    Asparagus    Beetle    (Crioceris    12-punctata    01.). 

Chittenden— Ybk.    U.    S.    Dept.   Agr.    f.    1896    (1897),   pp. 

349-352;  Bui.  66,  Bu.  Ent.,  pp.  9,  10,  1907. 
Asparagus  Miner  {Agromyza  simplex  Loew.).    L.  c,  pp.  1-5,  figs,  i 

and  2,  1907. 


BEANS  AND  PEAS 

General.  Chittenden — Ybk.  U.  S.  Dept.  Agr.  1898  (1899),  pp.  233- 
280,  figs. 

Bean  Leaf-beetle  (Cerotonia  trifurcata  Forst.  [C.  caminea  Fab.]) 
Chittenden — Bui.  23,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp 
30,  31,  1900. 

Pea  Aphis  {Ncctarophora  destructor  Johns.  [Nectarophora  pisi]) 
Chittenden — Bui.  23,  n.  s.,  Div..  Ent,  U.  S.  Dept.  Agr.,  pp. 
33-37,  fig-  9,  1900. 

Bean  Leaf-roller  (Eudamus  proteus  Linn.).  Chittenden — Bui 
2,3,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  92-96,  fig.  20,  1902. 

Lima-bean  Stem-borer  (Monoptilota  niibilclla  Hulst.).  Chitten- 
den— Bui.  22,,  n.  s„  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  9-17, 
1900. 

Smaller  Corn  Stalk-borer  (Elasmopalpus  lignosellus  Zell.).  Chit- 
tenden— Bui.  2^,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  17- 
22,  1900. 


BEETS  AND  SPINACH 

General.  Forbes  and  Hart — Bui  60,  Ills.  Agr.  Exp.  Sta.,  pp.*  397- 
532,  figs.  97,  pis.  I.-IX.,  1900.  (A  monographic  account 
with  bibliography)  ;  Chittenden — Bui.  43,  Div.  Ent.  U.  S. 
Dept.  Agr.,  pp.  1-71,  figs.,  1903.  (Short  accounts  of  princi- 
pal insect  enemies.) 

Leaf-miner  (Pegomya  vicina  Lint.).  Sirrine — 14th  Annual  Rept. 
Board  of  Control,  N.  Y.  Agr.  Exp.  Sta.,  pp.  625-633,  PI.  IV.. 
1896. 


BIBLIOGRAPHY  255 

Larger    Beet    Leaf -beetle    {Mono. via    puncticollis    Say.    [Galeruca 

maritima]).     Chittenden — Bui.   18,  n.  s.,  Div.   Ent.   U.   S. 

Dept.  Agr.,  p.  95,  1898. 
Beet   Aphis    {Pemphigus   betcr   Doane).      Doane — Bui.    42,    Wash. 

State  Agr.  Exp.  Sta.,  14  pp.,  4  figs.,  1900. 
Beet  Army  Worm   {Laphygma  exigua  Hbn.).     Chittenden — Bui. 

iS,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  37-46,  fig.,  1902. 
Beet    Webworm     {Loxostege    sticticalis    Guen.).      Gillette — 13th 

Ann.  Rept.  Colo.  Agr.  Exp.  Sta.,  pp.  128-130,  1900  (1901)  ; 

Bui.  98,  Agr.  Exp.  Sta.  Colo.,  pp.  3-12,  pis.  I.  and  II.,  1905. 

CABBAGE  AND  OTHER  COLE  CROPS 

Cabbage  Maggot  {Pcgotiiya  [Plwrbia]  brassiccr  Bouche).  Chit- 
tenden— Circ.  63,  Bu.  Ent.,  U.  S.  Dept.  Agr.,  pp.  3-6,  figs., 
1906;  Slingerland — Bui.  78,  Cornell  Univ.  Agr.  Exp.  Sta., 
pp.  481-577,  1894;  Smith — Bui.  200,  N.  J.  Agr.  Exp.  Sta.,  pp. 
1-27,  13  figs.,  1907. 

Imported  Cabbage  Worm  {Pontia  rapcc  Linn.).  Chittenden— 
Circ.  60,  Bu.  Ent.,  U.  S.   Dept.  Agr.,  8  pp.,  6  figs.,  April, 

1905- 
Cross-striped    Cabbage    Worm     {Evcrgcstis    [Pionca]     rimosalis 

Guen.).     Chittenden — Bui.   t,2„  n.  s.,  Div.  Ent.,  U.  S.  Dept. 

Agr.,  pp.  54-59,  1902. 
Cabbage   Looper    {Autographa  hrassiccc  Riley   [Plusia  brassiccc]). 

Chittenden — Bui.  S3>  "■  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp. 

60-69,  1902. 
Imported  Cabbage  Webworm  (Hellula  undalis  Fab.).     Chitten- 
den—Bui.  19,  n.  s,,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  51-57. 

1899. 

CUCUMBER,  MELON  AND  RELATED  PLANTS 

General.  Quaintance — Bui.  45,  Ga.  Agr.  Exp.  Sta.,  pp.  25-50,  figs., 
1899;  Smith— Bui.  94,  N.  J.  Agr.  Coll.  Exp.  Sta.,  pp.  3-40, 
1893. 

Striped  Cucumber  Beetle  {Diabrotica  vittata  Fab.).  Chitten- 
den—Bui.  19,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  48-51, 
1899;  Circ.  3i>  Div.  Ent.  U.  S.  Dept.  Agr.,  1898. 

Twelve-spotted  Cucumber  Beetle  {Diabrotica  duodecimpunctata 
Oliv.).     See  Corn  root-worms. 

Squash  Ladybird  {Epilachna  borcalis  Fab.).  Chittenden — Bui. 
19,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  11-20,  1899.  (In- 
cludes bibliography). 

Melon  Aphis  {Aphis  gossypii  Glov.  [Aphis  cucuuieris  Forbes]). 
Chittenden— Circ.  80,  Bu.  Ent.  U.  S.  Dept.  Agr.,  16  pp.,  6 
figs.,  1906. 

Squash  Bug  {Anasa  tristis  DeG.).  Chittenden— Circ.  39,  Div. 
Ent.  U.  S.  Dept.  Agr.,  1899 ;  .Bui.  19,  n.  s.,  Div.  Ent.,  pp.  20- 
28,  189 


256         INSECTS  INJURIOUS  TO  VEGETABLES 

Squash-vine  Borer    (Mclittia  satyriniformis  Hbn.    [^geria  cticur- 

bitce  and  Mclittia  ccto]).     Chittenden — Bui.  19,  n.  s.,  Div. 

Ent.  U.  S.  Dept.  Agr.,  pp.  34-40.  i899;  Circ.  38,  Div.  Ent. 

U.  S.  Dept.  Agr.,  1899- 
Pickle  Worm  {Diaphania  nitidalis  Cram.  [Eudioptis  and  Margaro- 

nia  nitidalis]).    Chittenden — Bui.  19,  n.  s.,  Div.  Ent.  U.  S. 

Dept  Agr.,  pp.  40-42,  1899;  Lintner — nth  Rept.  N.  Y.  St. 

Ent,    pp.    126-133,    1896;    Quaintance — Bui.    54,    Ga.    Agr. 

Exp.    Sta.,   pp.    73-91,   tigs.,    1901    (including   bibliography). 
Melon    Caterpillar    {Diapluinia    hyalinata    Linn.).      Chittenden — 

Bui.  19,  n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  42-44,  1899; 

Quaintance — Bui.  45,  Ga.  Agr.  Exp.  Sta.,  pp.  42-45,  1899. 

CELERY,  CARROT,  PARSLEY  AND  PARSNIP 

Celery    Looper    {Autographa    simplex    Guen.    [Plnsia    sintplc.v]). 

Chittenden — Bui.   S3>   "•   s.,   Div.   Ent.   U.   S.    Dept.   Agr.. 

pp.  73,  74-  1902. 
Greenhouse  Leaf-tyer   {Phlyctcenia  ferrugalis  Hubn.   [P.  rubigalis 

Guen.]).     Chittenden — Bui.  27,  n.  s.,  Div.  Ent.  U.  S.  Dept. 

Agr.,  pp.  7-26,  1901   (including  bibliography). 
Celery  Caterpillar  {Papilio  polyxcncs  Fab.  [P.  asterias]).    Davis — 

Bui.  102,  Mich.  Agr.  Exp.  Sta.,  pp.  21-24,  1893.     (For  mono- 
graphic  treatment   sec   works  of   Scudder  and  Edwards  on 

Butterflies.) 
Carrot   Rust-fly    {Psila   roscc   Fab.).     Chittenden— Bui.   33,   n.    s.. 

Div.  Ent.  U.  S.  Dept,  Agr.,  pp.  26-32,  1902. 
Carrot  Beetle   (Ligyriis  gibhosus  DeG.).     L.  c,  U.  S.  Dept.  Agr., 

pp.  32-S7,  1902. 
Parsnip  Webworm  (Dcprcssaria  hcracliana  DeG.).     Riley — Insect 

Life.  V.  I.,  pp.  94-98,  1888. 
Parsnip    Leaf-miner     {Acidia    fratria    Loew.     [Trypeta    fratria]). 

Coouillett— Insect  Life,  v.  VII.,  pp.  383,  384. 
Little    Negro    Bug    (Corinuiccna    pulicaria    Germ.).      Davis — Bui. 

102,  Mich.  Agr.  Exp.  Sta.,  pp.  13-18,  1893. 

SWEET  CORN 

General.     Forbes— 23rd  Rept.    St.   Ent.   Ills.,  pp.    1-273,   figs.,   pis., 

1905   (includes  bibliography). 
Seed-corn   Maggot    {Pcgoinya   fusciccps  Zett.    [Phorbia   fusciccps, 

Anthomvia   zccc,  etc.]).     Chittenden — Bui.   33,   n.   s.,   Div. 

Ent.  U.  "S.  Dept.  Agr.,  pp.  84-92,  1902 ;  Circ.  63,  Bu.  Ent.  U. 

S.  Dept.  Agr.,  pp.  1-3.  fig..  1906. 
Corn   Root-worms    (Diabrotica    longicornis    Say.    [D.    12-punctata 

01.]).     Chittenden— Circ.  59,  Bu.  Ent.  U.  S.  Dept.  Agr., 

8  pp.,  3  figs.,  1905. 
Corn  Bill-bugs.     General.      Forces— i6th  Rept.  St.  Ent..  Ills.,  pp.  58- 

74,  1890;  Bui.  79.  Ills.,  .\gr.'Exp.  St:i..  27  pp.,  1902. 


BIBLIOGRAPHY  257 

Southern  Corn  Bill-bug  (Sphenophorus  maidis  Chttn.  [Sph.  robus- 
tus  Authors]).  Forbes — L.  c. ;  Riley — Rept.  Comm.  Agr. 
1881-2,  pp.  138-142,  1883. 

Clay-colored  Bill-bug  {Sphenophorus  ccqualis  Linn.). — Treated  as 
Sph.  ochrciis  Lee,  by  Forbes,  1.  c. 

Northern  Corn  Bill-bug  {Sphenophorus  sece  Walsh). — Generally 
called  by  authors  5.  sculptilis  Uhl.,  1.  c. 

Larger  Corn  Stalk-borer  {Diatrcca  saccharalis  Zell.).  Howard — 
Circ.  16,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  1-3,  3  figs.,  1896. 

Smaller  Corn  Stalk-borer  {Elasmopalpus  lignosellus  Zell.).  Chit- 
tenden— Bui.  23,' n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  17- 
22,  1900. 

Corn-ear  Worm;  Cotton  BoUworm  {Heliothis  obsoleta  Fab.  [arm- 
iger  Hbn.]).  Quaintance — Farmers'  Bui.  191,  1904; 
QuAiNTANGE  and  Brues — Bui.  50,  Bu.  Ent.  U.  S.  Dept.  Agr., 
pp.  1-15S,  figs,  and  pis.,  1905   (includes  bibliography). 

POTATO,  EGGPLANT  AND  RELATED  PLANTS 

General.     Riley — Potato  Pests,  Orange  Judd  Co.,  N.  Y.,  pp.  1-108, 

figs.  48,  1876. 
Colorado  Potato  Beetle  (Lcptinotarsa  decemlineata  Say.  [Doryph- 

ora    lo-lineata]).     Chittenden — Circ.   87,    Bu.    Ent.    U.    S. 

Dept.  Agr.,  15  pp.,  6  figs.,  1907. 
Potato-tuber  Worm  or  Tobacco   Split-worm   {Phthorimcea  oper- 

ciilcUa    Zell.    [Lita    and    Gelechia    sohmella]).      Riley    and 

Howard — Insect  Life,  v.  IV.,  pp.  239-242,  1892;  Howard — 

Farmers'    Bui.    120,    U.    S.    Dept.    Agr.,    pp.    19-22,    1900; 

Clarke — Bui.  135,  Cal.  Agr.  Exp.  Sta.,  29  pp.,  7  figs.,  1901. 
Potato-stalk  Weevil   {Trichobaris  trinotata  Say.).     Chittenden^ 

Bui.  :iT„  n.  s.,  Div.  Ent,  U.  S.  Dept.  Agr.,  pp.  9-19,  1902. 
Tobacco    Flea-beetle    (Epitrix   parvula    Fab.)      Chittenden — Bui. 

19,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp.  85-87,  1899. 
Potato    or    Cucumber    Flea-beetle     {Epitrix    cucumeris    Harr.). 

Chittenden — Bui.  19,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  pp. 

89,  90,  1899. 

TOMATO 

Northern  Tobacco  Worm  or  Tomato  Worm  (Phlegethontius 
quinquemaculata  Haw.  [Protoparee  celeus]).  Howard — 
Farmers'  Bui.  120,  U.  S.  Dept.  Agr.,  pp.  10-14.  1900. 

Southern  Tobacco  Worm  or  Hornblower  {Phlegethontius  sexta 
Job.  [Protoparee  earolina]).  Howard — L.  c.,;  Alwood, 
Bui.  17,  n  .s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  72-74,  1898. 

Common  Stalk-borer  {Papaipema  nitela  Guen.  [Gortyna  nitela]). 
Smith— Rept.  Ent.  Dept.  N.  J.  Agr.  Coll.  Exp"  Sta.  f.  1905 
(1906),  pp.  584-587- 

Greenhouse  White  Fly  {Alcyrodes  vaporariorum  Westw.).  Mor- 
rill—Circ.  57,  Bu.  Ent.  U.  S.  Dept.  Agr.,  pp.  1-9,  fig.,  1905. 


258  INSECTS    INJURIOUS   TO   VEGETABLES 

SWEET  POTATO 

General.      Sanderson— Sweet    Potato    Insects,    Bui.    59,    Md.    Agr. 

Exp.  Sta.,  1900. 
Sweet-potato    Root-borer     (CyUis    formicarius    Fab.).  Conradi— 

Bui.  93,  Texas  Agr.  Exp.  Sta.,  pp.  3-16,  figs.,  1907. 
Larger  Sweet-potato  Savffiy  (Scliisocerus  pnvatus  Nort.).     Mar- 

LATT— Insect  Life  v.  V.,  pp.  24-27,  fig.  6,  1892. 
Sweet-potato    Flea-beetle    (Clurtociicma    coufinis    Cr.).      Smith — 

13th  Kept.  N.  J.  Agr.  Exp.  Sta.,  pp.  472-475.  1892. 
Mottled  Tortoise  Beetle  (Coptocychi  signifcra  Hbst.  [C.  guttata]). 

Sani)ek.son — L.  c. 
Golden  Tortoise  Beetle  (Coptocvcla  bicolor  Fab.  [C.  aurichalcea]). 

— L.  c. 

ONION 

Imported  Onion  Maggot  (Pcgomya  ccftoruin  Meade  [Anthomyia 
and  Fhorbia  ccfanim  Bouche]).  Chittenden — Circ.  63. 
Bu.  Ent.  U.  S.  Dept.  Agr.,  pp.  6,  7,  1906;  Smith  and  Dick- 
erson— Bui.  200,  N.  J.  Agr.  Exp.  Sta.,  27  pp.,  13  figs.,  1907. 

Onion  Thrips  (Thrips  tabaci  Lind.).  Pergande — Insect  Life,  v. 
VII.,  pp.  392-395- 


RHUBARB 

Rhubarb  Curculio   (Lixus  concavus  Say.).     Chittenden— Bui.  23, 
n.  s.,  Div.  Ent.  U.  S.  Dept.  Agr.,  pp.  61-69,  1900. 


INSECTICIDES 

1902.  Hinds,  W.  E. — Carbon  Bisulpbid  as  an  Insecticide.     Farmers' 

Bui.  145,  28  pp. 
1902-04.  Haywood,  J.  K. — Reports  on  Analyses  of  Insecticides.    Buls. 
68,  76  and  82,  Bu.  Chem.,  U.  S.  Dept.  of  Agr.  and  Farmers' 
Bui.  146,  16  pp. 

1903.  Marlatt,  C.  L. — Important  Insecticides.    Farmers'  Bui.  127,  U, 

S.  Dept.  Agr.,  46  pp.,  6  figs. 


INDEX 


PAGE 

Acidia  fratria    184,    185 

Agriotes   mancus    80 

Agrotis   ypsilon    52,    53 

Aleyrodes   vaporariorum   175 

Alfalfa  worm   xiv 

Anasa    tristis    161 — 164 

Anthonomus  arneotinctus    251 

eugenii    250 

Apanteles  glonieratus  ..15,   137,   138 
Aphides   ......10,  83—85,   127—130 

Aphis'  brassiccc     151  — 153 

gossypii    165—168,    214 

lions     11 

maidiradicis    189,    190 

rumicis     214 

Anachnida,   defined    4 

Army  worm,  fall   ...56,  59,  208,  209 

Arsenate    of    lead    32 

Arsenicals    30—34,   65,   137,   138 

harmless    33,   34 

Arsenic,   white    33 

Arsenite  of  copper    32 

lime    Zi 

Asparagus  beetle,  common    ..93 — 96 

work,    figured    X 

twelve-spotted      ....96,     97 

insects   injuring    93 — 97 

Autograplia  brassiccc   ....7,   140,   142 

Bait   for  insects    54,   55 

Barrel   spray   pumps    45 

Bean   cutworm    113 

ladybird    109,    110 

leaf-beetle   110,  111 

leaf-roller     112 

weevil,  common    102 — 104 

four-spotted     106 

Beans     and     peas,     insects     in- 
juring     100 — 119 

Beet  aphides   129,   130 

army  worm    125 

beetle.   Western    123 

insects   injurious   to    ..120 — 130 

leaf-beetle,   larger    122,   123 

webworm   125,    126 

Beetles,    defined 6 

Bill-bugs,   corn    195 — 199 

Birds,  beneficial 14 

Bisulphid  of  carbon. 42,  102,  133,  167 

Blister  beetles    66 — 69,   124 

Bollworm,   figured    xi 

see  also   Heliothis    113 

Bordeaux  mixture 29,  55,  56,  65 

Bran-mash    55,    138 

Bruchus  chinensis   104 — 106 

ohtccfus      102—104 

pisorum     100—102 

quadrimaculatus 106 


PAGE 

Brushing  methods  ..    ..27,  116,  11^ 

Bucket    pumps    45 

"Bud-worm"   of  corn    191 

"Bugging"     27 

Buhach,   or  pyrethrum    40 

Burning    over    fields    and    waste 

lands     18 

Butterflies,  defined 7 

Cabbage   aphis    151—153 

butterfly.    Southern    139 

flea-beetle.    Western     ..147,    148 

insects   injuring    131 — 154 

looper    7,    140 — 142 

maggot     131 — 135 

webworm,    imported    ..142 — 144 

worm,    cross-striped     140 

imported     136 — 139 

Cantharis   nuttalli    118,    119 

Carbolic-acid  emulsion    .37,   108,    132 
Carbon   bisulphid,    see    Bisulphid 
of    carbon 

Carneades  messoria    242,   243 

Carrot    beetle    185-187 

rust    fly    176—179 

Carrots,  insects   injurious  to  184 — 188 

Cassida   bivittata    239 

nigripes     239,     240 

Caterpillars,    miscellaneous    ..60 — 62 

Celatoria   diabroticce    157 

Celery    caterpillar    179,    180 

insects   injurious   to    ..176 — 186 

leaf-tyer      180—182 

looper    182,    183 

Centipedes,  briefly  defined 5 

Cerotoma   trifurcafa    110,    111 

Chwtocnema  coniinis   240,   241 

denticulata     212 

pulicaria     211 

Chinch  bug,   false   150,   151 

Chrysomelidae    62 — 66 

Clean  farming 22,   158,   159,   167 

Click    beetles     80,    81 

Cole   crop    insects    131 — 154 

Coleoptera    (beetles),    defined    6 

Collecting  insects,  see  also  hand- 
picking    27 

Compsomyia   macellaria,   figured    ..8 
Control    of   insects,    natural    ele- 
ments  jn    11 — 15 

Cooperation    in    control     of    in- 

_     .    sects    23—25 

Copidosoma    truncatella    142 

Copper  arsenite    32 

Coptocycla    bicolor    238 

^      g'lttata    238,    239 

Corimelccna   pulicaria    183 

259 


26o 


INDEX 


PACE 

Corn    bill-bugs    195—199 

cutworm     210,    211 

ear  worm 113,  207,  208 

insects  injuring    189 — 212 

root-aphis    189,    190 

root-worms     191 — 195 

stalk-borer,   larger    201—204 

stalk-borer,     smaller     ..204—207 

Corrosive    sublimate    37,    38 

Covering,    cloth    27,    28 

Cowpea    weevil 104 — 106 

Crioceris  asparagi    93 — 96 

12-puiictata     96,    97 

Crop    pests,    general    49 — 91 

rotation,    see    Rotation 

Crustacea,   briefly   defined    4 

Cucumber  beetle,  striped  ..156 — 159 
twelve-spotted  ..159,  191 
—193,    218 

flea-beetle     218 

insects    injuring     155 

Cultivation   methods    ..21,    132,    133, 

138,    139 
Cultural    methods,    see    Farming 
methods 

Currant    leafhopper     85 

Cutworm,  corn    210,   211 

dark-sided     246 

spotted    210,    211 

variegated     53,     54 

Cutworms    ..49—59,    113,    124,    145, 
210,   211,   242,  243,  246 

Cylas   formicarius    235,    236 

Depressaria   heracliana    ....187,    188 
Diabrotica   longicornis    . .  .  .194,    195 

\2-p%mctata    159,    191—193 

figured X"* 

vittata     156—159 

Diacrisia  virginica   60 

Diamond-back   moth    144,    145 

Diaphania   hyalinata    173 — 175 

nitidalis     171—173 

Diatraa    saccharalis    201 — 204 

Diedrocephala  versuta    117 

Diptera,  'defined    8 

Disking     21 

Disonycha  xanthomclana    ..121,    122 

Diversified   agriculture 20 

Domestic      animals,      destroying 

insects     79 

"Drill-worm"     191 

Driving  insects    68,   159 

Eggplant    flea-beetle     219 

Elasmopalpus   Hgnosellus    ..204 — 207 

Empoasca     iJavescens      85 

Entomology,  value  of  knowledge 

of 1 — ^3 

Eptcauta    lemniscata    67,    68 

maculata     68 

marginata 124 

pennsylvanica    220,    221 

vittata 67 

Epidapus   scabiei    226 — 228 

Epilachna  borealis   160,   161 

corrupta    109,    110 

Epitrix  cucumeris   217 — 219 

fuscula    219 

parvula     219,     220 


PAGE 

Eubadizon  schisoceri,  figured    ..241 

Eudamus    proteus    112 

Euphoria    inda     209,    210 

Euschistus   variolarius,   figured    ..10 

Eutettix    tenelta     128 

Euthrips   tritici,    figured    10 

Euxoa    messoria     246 

Evergestis   rimosalis    140 

Fall  army  worm 56 — 59 

harrowing    170 

plowing    21,   78,   82 

Farming     methods,     to     prevent 

insect  injury    ..16 — 25,  65,  66 

Feltia  annexa    53 

Fertilizers,  danger  from  organic.  108 

mineral     108 

"Fire   bug"    149 

Fish-oil   soap    38 

Flea-beetles    ..63—66,    121,    122,    146 
—  149,  211,   212 

Flies  defined   -8 

Formalin      ^o 

Fruit-chafer,    brown    209,    210 

Garden   flea-hopper    118 

webworm    61,    62 

Gas    lime    34,    35 

Granulated  cutworm    53 

Grasshoppers    69 — 73,    127 

Greasy  cutworm 52 

Ground  beetle,   fiery,  figured    12 

Gumbo,    insects    injuring     249 

Hair-streak,    gray    113,    114 

Halticini     63—66 

Halticus     uhleri     118 

Hand-picking   ..27,  56,  108,  105,   132 

Harlequin  cabbage  bug 148 — 150 

Heliophila    (Leucania)    unipuncta. 59 

Heliothis  obsoleta 113,   207,   208, 

233,  234 

Hellebore    35,   108,    135 

Hellula    undalis    142—144 

Hemiptera,   defined    9 

Heteroptera,    defined    9 

Hexapoda    (insects)    defined    5 

Hippodamia   convergens,   figured    ..6 

Homoptera,  defined   9 

Honey-dew     84,    85 

Hopper-dozers     27 

Hot  water,  as  insecticide.  .38,  39,  138 

Hymenoptera,  defined 8 

Insecticide     apparatus     43 — 47 

Insecticides    30 — 39,    78 

applying    47 

proprietary     42,    43 

Insects,      injurious,      determina- 
tion  of    . xii 

injury,    manifestations    of x 

life   history   of    2 

classification    3 — 6 

natural   elements  in  control 

of     11—15 

predaceous     12 

useful    14 

Inspection,     farm     22,    23 

June   beetles    73 — 79 

Kerosene  and   sand    108 

emulsion   ..16,  37,  65,   116,   138, 
167,    178 


INDEX 


261 


PAGE 

Knapsack  sprayer    44 

Lace-wing   fly,   figured    11 

Lach)iosterna  arcuata   76 

cribrosa     77 

farcta     77 

fusca   76 

Ladybird,   convergent,   figured    ....6 

spotted    95 

Ladybirds     13 

Laphygma    exigua    135 

frugiperda     ..56—59,     208,     209 

Leaf-beetles    62—66,    121—124 

-hoppers    .85—87,    117,    127,    128 

-miners   127,   153,   154 

Lebia    grandis    13,    217 

Lepidoptera,   defined    7 

Lepti)iotarsa  decemliucata   .214 — 217 

Lettuce   earth-louse    249 

insects    injurious    to    ..248,    249 

Ligyrus    gibbosus     185 — 187 

Lime    34 

Li.uis   concavus    247 

Locusts     69 — 73 

London  purple    32 

Loxostege  similalis 61,  62 

sticticalis    125,    126 

Lygus     pratensis     87,     88 

Macrobasis    unicolor     119 

MancaselhiS  brachyurus,  figured    ..4 

May  beetles 73 — 79 

Mealy-bugs     243 

Mechanical   methods   of  destroy- 
ing   insects    26 — 29 

Megilla    maculata     95 

Melanoplus  differentialis   71 

femur-rubrum    70 

spretus    9,    70,    71 

Melanotus  communis   80,  81 

Melittia  saiyrimformis 168 — 171 

Meloida      66 — 69 

Melon  aphis   85,   165 — 168 

caterpillar    173 — 175 

insects   injuring    155 — 175 

Millipedes,    briefly    defined    5 

Milyas  cinctiis,   figured    12 

Mites,    defined    4 

Monocrepidius    vespertinus,    fig- 
ured      212 

Monoxia    consputa     123 

puncticolUs    122,    123 

Moths,   defined    7 

Murgantia    histrionica    148 — 150 

Myriopoda,   defined    5 

Natural    elements   in    control    of 

insects 11 — 15 

Ncctarophora  cucitrbita   165 

destructor     114 — 117 

erigeronensis     229 

Negro  bug,  little    183 

Neuroptera,    defined    10 

Nicotine   extracts   and   powders    .  .41 

Noctua    clandestina     51 

c-nigrum     210,    211 

Nozzles,    spraying    47 

Nysius  angustatus    150,    151 

minutus    151 

Ogdoconta    cinereola    113 


PAGE 

Okra,  insects  injurious  to 249 

Oncometopia    undata     249 

Onion    fly,   black    24S 

insects   injuring    244 — 246 

maggot,   imported   245 

thrips    89,    99 

Orthoptera,  defined    9 

Papaipema    nitcla     199 — 201 

Papiho    polyxenes    179,    180 

Parasites,    useful    14 

Paris  green   30 — 32 

Parsley,  insects  injuring    ..184 — 188 

Parsnip  leaf-miner    184,   185 

vvebworm    187,    188 

Parsnips,   insects  injuring    .184 — 188 

Pea  aphis 114—117 

moth    Ill,    112 

weevil      100 — 102 

Peas,   insects   injuring    ....100 — 119 

Pegomya    brassica-     131 — 135 

cepetorum     245 

fusciceps    106 — 109,    135 

Pemphigus    betes    129 

Pepper,    insects   injuring    250 

Pendroma    saucia    53,    54 

Phcedon    aruginosa    147 

Phlegethontius    qtiinquemacul-ata 

229—232 

sexta    -.232,   233 

Phlyctania    ferrugalis     180 — 182 

Phihorimaa    opercitlella    ...224 — 226 

Phyllotreta  pusilla    147,    148 

vittata     146,     147 

Physopoda,   defined    10 

Pickle  worm    171 

Pie-plant,  insects  injuring.  .246 — 248 

Plant-bug,    brown,    figured    10 

tarnished,    figured    11 

Plant-bugs     ..10,     83,     87,    88,     117, 

118,    127,    128,    148—151 
Planting   to   avoid   insect   injury 

17,   158 
Plant-lice,  see  Aphis  and  Aphides 

Plusia  simplex 182,   183 

Phitella    maculipennis    ...1.144,   145 

Podisus    maciiliventris    95 

Poisoned    baits     54,    83 

Poisons,    contact    36 — 39 

stomach     30,    35 

Polistes    bellicosus,    figured    5 

Pontia   napi   139,   140 

protodice    139 

rapa    136—139 

Potato    beetle,    Colorado    ..214—217 

flea-beetle     217—219 

insects   injuring    213 — 228 

scab  gnat   226 

stalk  weevil   221—224 

tuber  worm   224 — 226 

Potherb    butterfly    139,    140 

Preventives    16,    78,    79 

Proprietary  insecticides 42,  43 

Protection  of  plants   55 

Pruning,  as  insect   remedy    28 

Psila   rasa    176—179 

Psvlliodes  punctulafa    248 

Pteromaluspuparum. 14,  15,  137,  138 
Pyrethrum..Z9,  40,  65,  138,  159,   167 


262 


PAGE 

Red-legged  locust    70 

Red  spider 91 

Repellents     28,     29 

Rhisobius   lactuca 249 

Rhopalosifhiim  dianthi   ....151,   214 

solam    229 

Rhubarb  curculio  247 

flea-beetle   248 

insects   injuring    246 — 248 

Rocky    mountain   locust    ..9,    70,    71 

Root-maggots     131 — 135 

Rotation,   crop    19,    79,   82,   83 

Salsify,   insects   injuring    250 

Scaptomysa   fiaveola    153,    154 

Scheele's   green    32 

Schizocerus  ebenus    241 

privatus     241,     242 

Screw-worm,    figured     8 

Seed-corn    maggot    ...106—109,    135 

Semasia   nigricana    Ill,    112 

Sharpshooter,    waved    249 

Sigalphus  curculionis   223 

Soap,    insecticide    38,    65,    167 

Solaier-bug,   bordered    12,   95 

spined     95 

Sowing,    late     1 78 

Sphenophorus   aqualis    198 

callosus     195 

maidis    196,     197 

sea    .197,    198 

Spinach   flea-beetle    121,    122 

insects   injuring    120 — 130 

Sprayer,  knapsack    44 

Spraying    36,   37,   43—47 

Spraying    apparatus    43 — 47 

Spring  plowing 170 

Squash  bug   161—164 

ladybird   160,    161 

-vine   borer    158 — 171 

Stalk-borer,    common    199 — 201 

Stiretrus   anchorago    95 

Suffocation,     insecticides    which 

kill    by    39—42 

Sugar-beet   leaf  hopper    128 

Sulphur     41,     42 


PAGE 

Sweet   corn,   insects   injuring 

189—212 
Sweet-potato   beetle,    two-striped. 239 

flea-beetle     240,    241 

insects  affecting 235 — 243 

root-borer    235,   236 

sawflies    241,   242 

tortoise    beetles    236 — 238 

Syrphus   ribesii,    figured    13 

Systena    blanda    63,    64 

tceniata     64,     65 

Tarnished   plant-bug    I,   87,   88 

Tarred    paper    cards    133 — 135 

Tetranychus  bimaculatus   91 

Thecla  melinus   113,    114 

Thousand-legged  worms 5 

Thrips    10,    89—91 

tabaci     89,     90 

tritici     90,     91 

Tipliia   inornata    78 

Tobacco,  as  insecticide 40 

flea-beetle     219.    220 

Tomato   fruit   worm 23i,   234 

insects  injurious  to   ...229 — 234 

worms     229—233 

Tortoise  beetles    237 — 240 

Trap  crops   .138,    139,   158,    159,   170 

Trapping  insects    28 

Trichobaris  trinotata 221 — 224 

Trichopoda  pennipes   163,    164 

Tritoxa    iiexa    245 

Turnip  flea-beetle,   striped    .146,    147 
leaf-miner,   irnported    ..153,    154 

Tychca   brevicornis    130 

N'ariegated   cutworm    53,    54 

Vermorel    nozzle    47 

Water-cress    leaf-beetle     147 

sowbug,    illustrated    4 

Whale-oil    soap     38 

Wheat  thrips   90,  91 

wireworm   80 

White   fly   175 

White  grubs    73—79,    130 

Wireworms   79—83,    130,    212 

W-marked   cutworm    51 

Yellow  bear    60 


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Fruit  Harvesting,  Storing,  Marketing 

By  F.  A.  Waugh.  A  practical  guide  to  the  picking,  stor- 
ing, shipping  and  marketing  of  fruit.  The  principal  subjects 
covered  are  the  fruit  market,  fruit  picking,  sorting  and  pack- 
ing, the  fruit  storage,  evaporating,  canning,  statistics  of  the 
fruit  trade,  fruit  package  laws,  commission  dealers  and  dealing, 
cold  storage,  etc.,  etc.  No  progressive  fruit  grower  can  afford 
to  be  without  this  most  valuable  book.  Illustrated.  232  pages. 
5x7   inches.     Cloth $1.00 

Systematic  Pomology 

By  F.  A.  Waugh,  professor  of  horticulture  and  landscape 
gardening  in  the  Massachusetts  agricultural  college,  formerly 
of  the  university  of  Vermont.  This  is  the  first  book  in  the 
English  language  which  has  ever  made  the  attempt  at  a  com- 
plete and  comprehensive  treatment  of  systematic  pomology. 
It  presents  clearly  and  in  detail  the  whole  method  by  which 
fruits  are  studied.  The  book  is  suitably  illustrated.  288  pages. 
5x7  inches.    Cloth $1.00 


Feeding  Farm  Animals 

By  Professor  Thomas  Shaw.  This  book  is  intended  alike 
for  the  student  and  the  farmer.  The  author  has  succeeded  in 
giving  in  regular  and  orderly  sequence,  and  in  language  so 
simple  that  a  child  can  understand  it,  the  principles  that  govern 
the  science  and  practice  of  feeding  farm  animals.  Professor 
Shaw  is  certainly  to  be  congratulated  on  the  successful  manner 
in  which  he  has  accomplished  a  most  difficult  task.  His  book 
is  unquestionably  the  most  practical  work  which  has  appeared 
on  the  subject  of  feeding  farm  animals.  Illustrated.  5^  x  8 
inches.    Upward  of  500  pages.    Cloth $2.00 


Profitable  Dairying 

By  C.  L.  Peck.  A  practical  guide  to  successful  dairy  man- 
agement. The  treatment  of  the  entire  subject  is  thoroughly 
practical,  being  principally  a  description  of  the  methods  prac- 
ticed by  the  author.  A  specially  valuable  part  of  this  book 
consists  of  a  minute  description  of  the  far-famed  model  dairy 
farm  of  Rev.  J.  D.  Detrich,  near  Philadelphia,  Pa.  On  this 
farm  of  fifteen  acres,  which  tvi^enty  years  ago  could  not  main- 
tain one  horse  and  two  cows,  there  are  now  kept  twenty-seven 
dairy  cattle,  in  addition  to  two  horses.  All  the  roughage, 
litter,  bedding,  etc.,  necessary  for  these  animals  are  grown  on 
these  fifteen  acres,  more  than  most  farmers  could  accomplish 
on  one  hundred  acres.  Illustrated.  5x7  inches.  200  pages. 
Cloth $0.75 


Practical  Dairy  Bacteriology 

By  Dr.  H.  W.  Conn,  of  Wesleyan  University.  A  complete 
exposition  of  important  facts  concerning  the  relation  of  bacteria 
to  various  problems  related  to  milk.  A  book  for  the  class- 
room, laboratory,  factory  and  farm.  Equally  useful  to  the 
teacher,  student,  factory  man  and  practical  dairyman.  Fully 
illustrated  with  83  original  pictures.  340  pages.  Cloth. 
SYz  X  8  inches $1.25 


Modern    Methods  of  Testing    Milk  and   Milk 
Products 

By  L.  L.  VanSlyke.  This  is  a  clear  and  concise  discussion 
of  the  approved  methods  of  testing  milk  and  milk  products. 
All  the  questions  involved  in  the  various  methods  of  testing 
milk  and  cream  are  handled  with  rare  skill  and  yet  in  so  plain 
a  manner  that  they  can  be  fully  understood  by  all.  The  book 
should  be  in  the  hands  of  every  dairyman,  teacher  or  student. 
Illustrated.     214  pages.     5x7  inches $0.75 


Rural  School  Agriculture 

By  Charles  W.  Davis.  A  book  intended  for  the  use  of 
both  teachers  and  pupils.  Its  aim  is  to  enlist  the  interest  of 
the  boys  of  the  farm  and  awaken  in  their  minds  the  fact  that 
the  problems  of  the  farm  are  great  enough  to  command  all 
the  brain  power  they  can  summon.  The  book  is  a  manual 
of  exercises  covering  many  phases  of  agriculture,  and  it  may 
be  used  with  any  text-book  of  agriculture,  or  without  a  text- 
book. The  exercises  will  enable  the  student  to  think,  and  to 
work  out  the  scientific  principles  underlying  some  of  the  most 
important  agricultural  operations.  The  author  feels  that  in  the 
teaching  of  agriculture  in  the  rural  schools,  the  laboratory  phase 
is  almost  entirely  neglected.  If  aji  experiment  helps  the  pupil  to 
think,  or  makes  his  conceptions  clearer,  it  fills  a  useful  purpose, 
and  eventually  prepares  for  successful  work  upon  the  farm. 
The  successful  farmer  of  the  future  must  be  an  experimenter 
in  a  small  way.  Following  many  of  the  exercises  are  a  number 
of  questions  which  prepare  the  way  for  further  research  work. 
The  material  needed  for  performing  the  experiments  is  simple, 
and  can  be  devised  by  the  teacher  and  pupils,  or  brought  from 
the  homes.    Illustrated.    300  pages.    Cloth.    5x7  inches.    $1.00 

Agriculture  Through  the  Laboratory  and  School 
Garden 

By  C.  R.  Jackson  and  Mrs.  L.  S.  Daugherty.  As  its  name 
implies,  this  book  gives  explicit  directions  for  actual  work  in 
the  laboratory  and  the  school  garden,  through  which  agri- 
cultural principles  may  be  taught.  The  author's  aim  has  been 
to  present  actual  experimental  work  in  every  phase  of  the 
subject  possible,  and  to  state  the  directions  for  such  work  so 
that  the  student  can  perform  it  independently  of  the  teacher, 
and  to  state  them  in  such  a  way  that  the  results  will  not  be 
suggested  by  these  directions.  One  must  perform  the  experi- 
ment to  ascertain  the  result.  It  embodies  in  the  text  a  com- 
prehensive, practical,  scientific,  yet  simple  discussion  of  such 
facts  as  are  necessary  to  the  understanding  of  many  of  the 
agricultural  principles  involved  in  every-day  life.  The  book, 
although  primarily  intended  for  use  in  schools,  is  equally 
valuable  to  any  one  desiring  to  obtain  in  an  easy  and  pleasing 
manner  a  general  knowledge  of  elementary  agriculture.  Fully 
illustrated.    5/^x8  inches.    462  pages.    Cloth.     Net     .     $1.50 

Soil  Physics  Laboratory  Guide 

By  W.  G.  Stevenson  and  I.  O.  Schaub.  A  carefully  out- 
lined series  of  experiments  in  soil  physics.  A  portion  of  the 
experiments  outlined  in  this  guide  have  been  used  quite  gen- 
erally in  recent  years.  The  exercises  (of  which  there  are  40) 
are  listed  in  a  logical  order  with  reference  to  their  relation 
to  each  other  and  the  skill  required  on  the  part  of  the  student. 
Illustrated.    About  100  pages.    5x7  inches.     Cloth.     .     $0.50 


Farmer*s  Cyclopedia 
of  Agriculture    ^    ^ 

A  Compe?idium  of  Agricultural  Science  and  PraSlice 
on  Farm,  Orchard  and  Garden  Crops,  and  the 
Feeding  and  Diseases  of  Farm  Animals       :     :      •     : 

'By    EARLEY  VERNON  WILCOX,  Ph.D 
aii^   CLARENCE  BEAMAN  SMITH.  M.S 

Associate  Editors  in  the  Office  of  Experiment  Stations,   United  States 
Department  of  Agriculture 


THIS  is  a  new,  practical,  and  complete  pres- 
entation of  the  whole  subject  of  agricul- 
ture in  its  broadest  sense.  It  is  designed 
for  the  use  of  agriculturists  who  de- 
sire up-to-date,  reliable  information  on 
all  matters  pertaining  to  crops  and  stock,  but 
more  particularly  for  the  actual  farmer.  The 
volume  contains 

Detzdled  directions  for  the  culture  of  every 

important   field,    orchard,    and    g'arden    crop 

grown  in  America,  together  with  descriptions  of 
their  chief  insect  pests  and  fungous  diseases,  and 
remedies  for  their  control.  It  contains  an  ac- 
count of  modern  methods  in  feeding  and  handling 
all  farm  stock,  including  poultry.  The  diseases 
which  afifect  different  farm  animals  and  poultry 
are  described,  and  the  most  recent  remedies  sug- 
gested for  controlling  them. 

Every  bit  of  this  vast  mass  of  new  and  useful 
information  is  authoritative,  practical,  and  easily 
found,  and  no  effort  has  been  spared  to  include 
all  desirable  details.  There  are  between  6,000 
and  7,000  topics  covered  in  these  references,  and 
it  contains  700  royal  8vo  pages  and  nearly  500 
suberb  half-tone  and  other  original  illustrations, 
making  the  most  perfect  Cyclopedia  of  Agricul- 
ture ever  attempted. 

Handsomely  bound  in  cloth,  ^3.50;    half 
{•Oery  jutnpiuouj),  ■^4-. 50,  pojipaid 

ORANGE  JUDD    COMPANY,   "'^'  ^^'^yette  «-t.  New  York,  tY. 


Marquette  Building,  Chicago,  UL 


